oaf: A clumsy, foolish person. Variant of “auph” < Old Norse “alfr”=an elf or goblin’s half-witted child.
oar: Wooden (usually) pole with a blade at the end used to propel a boat. From Old Norse “ar”=oar.
oast: A round building with a pointed top used for drying hops. Old English “ast”=kiln < Indo-European “ad”=fire or funeral fire.
oath: Formal and serious promise, usual invoking a god as witness to the truth. From Old English “eth”=an oath < possibly Greek “oitos”=fate
obacerate: To close ones mouth. Latin “obacerare”=to contradict < “ob”=against + ? “acer”=sharp.
obambulate: To wander here and there; walk about. Latin “obambulere”=to walk about < “ob”=to, in the direction of + “ambulere”=to walk.
obarmate: To arm against. Latin “obarmare”=to arm < “ob-“=against + “armare”=to arm.
obdurate: Hardened against feeling; hard-hearted. From Latin “obduratus”=hardened < “ob-“=against + “durus”=hard.
obeisance: Respect paid to someone or something, often shown by bending your head or the upper part of your body. Anglo-Norman “obeisance”=obedience < Latin “oboedire”=obey, listen to, pay attention < “ob-“=towards + “audire”=to hear
obelisk: Tapering, four-sided pillar or column of stone with a pyramidal top. Latin “obelisqus” < Greek “obeliskos”=small spit.
obese: Very fat; extremely overweight. Latin “obesus”=fat, plump, stout < “ob-“=intensifying prefix + “edere”=to eat.
obey: Follow the commands of someone. From Old French “obeir” < Latin “obedire”=to pay attention < “ob-“=towards/to + “audere”=to hear
obfuscate: To make obscure or difficult to follow. From Latin “obfuscare”=to darken, which comes from “ob”=over + “fuscus”=dark.
obituary: List of recorded deaths, often printed in a newspaper. From Latin “obire”=go to meet + “-ary”=connected to. Going to meet death.
oblate: A sphere that is flattened at the top and bottom; pumpkin shaped. Latin “oblatus”=flattened < “ob-“=toward + “latus” < “prolatus”=lengthened.
oblectation: Delight, pleasure, or enjoyment; an instance of this. Latin “oblectare”=to please or delight < “ob-“=completely + “lactare”=to entice + “-ion”=noun-forming suffix.
oblige: To make someone legally/morally bound to do something. Anglo-Norman “obliger”=bind by oath < Latin “ob-“=toward + “ligare”=to bind.
obliterate: To wipe out; to do away with. Latin “obliterare”=to cause to be forgotten, to erase < “ob-“=against + “littera”=letter, something written.
oblivion: When something is totally forgotten or no longer important. Anglo-Norman “oblivion”=forgetfulness < Latin “oblivisci”=to forget
oblivious: Not noticing things happening around you. From Latin “oblivisci”=to forget < “ob”=over + Greek “leios”=smooth.
obliviscence: The deterioration of the ability to remember things or perform a task after you’ve finished learning it. Latin “oblivisci”=to forget or to wipe away or smooth over < “ob-“=away + “levis”=smooth + “-ence”=noun-forming suffix.
oblocutor: A person who contradicts or slanders. Latin “ob-“=against + “loqui”=to speak + “-or”=suffix meaning “a person who…”
obloquy: Strong public condemnation. Anglo-Norman “obloquie” < Latin “obloquium”=contradiction < “ob”=against + “loqui”=to speak.
obmutescence: The act of becoming mute or speechless. Latin “ob-“=toward + “mutus”=mute + “-escere”=adjective-forming suffix.
obnoxious: Extremely unpleasant; offensive. Latin “obnoxius”=exposed to harm < “ob-“=toward + “noxa”=hurt + “-ius”=adjective-making suffix
obnubilate: Obscure; cloudy; indefinite. Latin “obnubilare”=to darken or obscure < “ob-“=in front of + “nubes”=cloud.
obreption: The act of creeping up unseen on someone. Latin “obrepare”=to creep up on < “ob-“=move toward + “repere”=to creep.
obscene: Offensively or grossly indecent, lewd. Latin “obscenus”=disgusting, indecent. Possibly from “ob”=onto + “caenum”=filth.
obscurantism: The practice of deliberately stopping ideas and facts from being known. German “obskurant” < Latin “obscurare”=to hide + “-ism”=suffix meaning the action or process of doing something.
obscure: Dark, dim, or unclear. From Latin “obscurus”=covered over < “ob-“=over + “scurus”=covered. c.f Latin “scutum”=shield.
obsequious: Eager to please in a servile way. From Latin “obsequiosus”=compliant, obedient < “ob”=toward + “sequi”=to follow + “ous”=full of.
observer: One who watches. Middle English “oberve”=to watch < Latin “ob-“=toward + “servare”=to attend to, to look at.
obsession: Persistent, unhealthy, compulsive thought. Latin “obsessio”=to put under siege < “obsidere”=”ob”=against + “sedere”=to sit.
obsidian: A hard, black, glassy volcanic rock. Latin “obsianus” < “Obsius”=a Roman who found such a stone in Ethiopia.
obsolete: Not in use any more, usually as a result of being replaced by something better. Lain “obsoletus”=worn out, grown old < “obsolescere” < “ob-“=away from + “solere”=to use, to be accustomed to.
obstacle: Something that blocks the way. Middle French “obstacle” < Latin “obstare”=to stand in the way < “ob”=against”+”stare”=stand.
obstinate: Refusing to change ones opinion despite persuasion. Latin “obstinare”=to persist < “ob-“=intensifier + “stare”=to stand.
obstreperous: Noisy and aggressive. Latin “obstreperus”=clamorous < “ob-“=completely + “strepare”=to make a noise + “-ous”=full of.
obtain: To get something that you want, especially through your own effort, skill, or work. Anglo-Norman “obtenir”=to gain, acheive < Latin “obtinere”=to succeed, win, be victorious < “ob-“=in front of (or as a general intensifier) +”tenere”=to hold, keep.
obtrusive: Being excessively or annoyingly self-assertive. Latin “obtrudere”=to thrust against < “ob-“=against + “trudere”=to thrust.
obtund: To make numb; to dull the sensitivity of. Latin “obtundere” < “ob-“=against + “tundere”=to beat with a stick (until numb).
obumbrative: Overshadowing; casting a shadow over something. Latin “obumbrare”=to shade or darken < “ob-“=over + “umbrare”=to shadow.
obverse: Something that is the opposite of something else; the side of a coin or medal bearing the head or primary design. Latin “obversus”=opposite < “obvertere”=to turn in an opposite direction < “ob-“=towards + “vertere”=to turn.
obviate: To remove a need or difficulty. Latin “obviare”=to go against < “ob-“=prefix meaning “against” + “via”=way or road.
occaecate: To make blind. Latin “occaecare”=to blind, block out light, hide from view < “ob-” prefix with the sense “completely” + “caecare”=to make blind < “caecus”=blind.
occidental: Of or referring to countries in the West. Anglo-Norman “occident”=west < Latin “occidens”=place where the sun sets.
occlude: Block passage through. Latin “occludere”=to shut up, close < “ob-“=against + “claudere”=to close.
ocean: A very large expanse of sea water. Old French “occean” < Latin “Oceanus” < Greek “okeanos”=great stream encircling the earth.
oche: The line behind which darts players stand when throwing. Uncertain origin but perhaps related to Middle French “ocher”=to cut a notch into < Old French “oche”=a notch.
ochlocracy: Government by the people; mob rule. French “ochlocratie” < Greek “oklokratia”=mob rule < “oklos”=crowd + “kratia”=rule.
ochlophobia: Fear of crowds. Greek “oklos”=crowds + “phobos”=fearing or dreading.
octave: The difference in sound between the first and eighth note on a musical scale; a group or stanza of eight lines of verse. Latin “octava” < “octavus”=eighth.
octogamy: Marriage with 8 spouses (at the same time or successively. Latin “octo”=eight + “gamus”=marriage < Greek “gamos”=marriage.
octovirate: A council or group of eight men; a body of eight. Latin “octovire”=a member of an eight-man council < “octo”=eight + “vir”=man, manly, masculine.
oculate: Sharp sighted, observant. Latin “oculatus”=having good sight < “oculus”=eye + “-atus”=adjective-forming suffix.
odalisque: A female slave or concubine in a harem; an exotic, sexually attractive woman; a representation of a sexually attractive figure in art. Turkish “odalik” =chamber, room + “lik”=suffix expressing function.
ode: Classical poem of a kind originally meant to be sung. Middle French “ode” < Latin “oda” < Greek “oide”=song < “aeidein”=to sing.
odeum: Roof-covered building used primarily for musical performances. Latin “odeum” < Greek “oideion” < “ode”=poem meant to be sung.
odious: Extremely unpleasant or disgusting; deserving of hatred. Anglo-Norman “odiose” < Latin “odiosus” =offensive < “odium”=hatred.
odium: Hatred and disgust. From Latin “odium”=hatred or ill-will < “odisse”=to hate.
oenomaniac: Someone with a mania or craving for alcohol. Greek “oinos”=wine + “mania”=excessive desire.
oenophile: A wine lover. Greek “oinos”=wine + “-filos”=beloved, dear.
off-beat: Unusual, weird, strange. From Old English “of”=away from + “beatan”=hit/thrash. From the musical sense of odd tempo.
officious: Intrusive in a meddling or offensive manner. Latin “officiosus”=dutiful < “officium”=task, duty + “-osus”=full of.
ogertful: Proud, haughty, fastidious, affected. Middle English “ogart”=arrogance, pride < ?Old Norse “agjarn”=ambitious, insolent.
ogre: Mythical man-eating giant. French “ogre” < ?Latin “Orcus”=underworld god, the punisher of broken oaths.
ohrwurm: A song you can’t get out of your head. German “ohrwurm” < “ohr”=ear + “wurm”=worm. Sometimes the English “earworm” is used.
ointment: A soft cream that you rub into your body, often as a medical treatment or as an attempt to software the skin. Old French “oignement” < Latin “unguere”=to anoint < “unguentum”=a soft lubricant cream or oil.
okra: A green, finger-like vegetable used in cooking, especially in Asia and the southern US. West African Igbo “okuru.”
oleaginous: Resembling or having the properties of oil; of people, having an offensively ingratiating manner. French “oléagineux” < Latin “oleaginus” = from the olice tree < “oleum”=oil.
olfactory: Of or relating to the sense of smell or the act of smelling. Latin “olfactorium”=a bottle or substance for smelling < “olfacere”=to smell + “-ory”=adjective-forming suffix with the sense of “involving an action.”
olid: Having a strong and unpleasant smell; fetid, rank. Latin “olidus”=stinking, smelling < “olere”=to smell.
oligopoly: Control of all or most of a business activity by a few companies. Latin “oligo” < Greek “oligos”=small number + “polein”=to sell.
oligopsony: A market condition in which a small number of buyers dominates or controls trade in a commodity, product, or service. Greek “oligos”=small number + “polein”=to sell.
olisbos: A penis-shaped sex toy. Greek “olisbein”=to slip or glide + “-bos”=noun-forming suffix.
olympiad: Event where modern or ancient Greek games are held. Greek “Olympos”=mountain home of the Greek gods.
omadhaun: A foolish person; an idiot. Irish “amadan.”
ombrifuge: Anything providing shelter from the rain. From Greek “ombros”=shower of rain + Latin “-fugere”=to flee from.
omega: Last letter of the Greek alphabet. Latin “omega” < Greek “o mega”=great “O”, contrast to “o mikron”=little “O.”
ominous: Giving the impression something bad is about to happen. Latin “ominosus”=portentous < “omin”=omen, sign + “-ous”=full of.
omit: To leave (something) out; to exclude. Latin “omittere”=to leave undone, to neglect < “ob-“=down + “mittere”=to let go.
omniana: A collection of notes, jottings, or short pieces of writing on all or many topics. Latin “omnia”=all things + “-ana”=suffix originally meaning “collections of notable sayings or ‘table-talk’ by authors.
omnibus: A public vehicle that carries many passengers (shortened to “bus”). Latin “omnibus”=for all < “omni”=all.
omniloquent: Speaking of all things or on all subjects. Latin “omnis”=all + “loquent”=speaking in the manner of < “loqui”=to speak.
omnipotent: All powerful and without limits. Anglo-Norman and Middle French “omnipotent” < Latin “omnipotens” < “omni”=ain all ways” + “potent”=powerful, influential, mighty.
omnipresent: Widely or constantly found; common or widespread. Latin “omnipraesens” < “omni-“=in all ways + “praesens”=being in the same place.
omniscient: All-knowing, typically used to refer to a god. Latin “omni”=all things + “scient”=knowledgeable < “scire”=to know.
on: Related to a local position outside of, but in contact with or close to, a surface. From Old English “on” < Greek “ana”=on, upon, or up.
onager: An endangered wild ass found in northern Iran. Latin “onager” < Greek “onagros” < “onos”=ass + “agrios”=wild.
oneirology: The study, or interpretation, of dreams. Greek “oneiros”=dream + “ology”=study of < Greek “logos”=word.
onerous: Not easily borne; wearing. From Middle French “onéreux ” < Latin “onerosus” < “onus+=load, burden + “-ous”=full of.
oniomania: Compulsive urge to buy things. Greek “onios”=for sale < “oneisthai”=to buy things + “mania”=madness.
onion: Round white many-layered vegetable with a brown, red, or white skin. Old French “oignon” < Latin “unio”=a single large pearl.
onology: Foolish talk; talking like an ass. Greek “onos”=ass + “-logy”=related to speaking, talking, and/or words.
onomancy: Fortune telling using the letters of a person’s name. Latin “onomantia” < Greek “onomia”=name + “manteia”=divination by.
onomastics: The study of proper names (people, places etc.) From Greek “onomastikos”=pertaining to words.
onomatology: The science/study of the formation of names. Latin “onomatologia” < Greek “onomato”=related to words + “-ology”=the study of
onomatopoeia: A word made from a sound e.g. clunk, meow, splash, whoosh. From Greek “onoma”=name/word + “poiein”=to make or compose.
onslaught: Sudden and severe onset of trouble. Early Modern Dutch “aanslag”=attack < “aan”=on + “schlact”=slay/slaughter.
onus: Hard or difficult concern; responsibility, burden or duty. From Latin “onus” < burden. Possibly from Sanskrit “anas”=wagon.
oofless: Having no money; temporarily poor. Yiddish “ooftish”=money < “gelt afn (oof) tish”=money on the table + Old English “-leas”=without
ookpik: Small doll resembling an arctic owl, adopted as a distinctively Canadian symbol or souvenir.Inuit “ukpik”=snowy owl.
oologize: To collect bird’s eggs; to take eggs from a nest. Latin “oology”=the study of bird eggs < “oo-“=related to eggs + “-logy”=the science/study of.
oology: The study/collection of birds’ eggs. Greek “oo”=egg, ovum + “-logia”=the study or science of (in this case, eggs).
oolong: Dark colored variety of China tea. Chinese “wulong” < “wu”=black + “long”=dragon, imperial.
oom: South African form of address to an older man, especially an uncle. Afrikaans “oom” < Dutch “oom”=uncle < West Germanic.
oonchook: Foolish person, especially a female. Irish “oinseach”=foolish woman, clown < Early Irish “oinmit”=fool + “-seach”=female suffix.
oont: Anglo-Indian and Australian colloquialism for a camel. Hindi “ut” < Sanskrit “ustra”=camel.
ooscopy: Divining the future using birds’ eggs. Greek “ooskopia”=inspection of eggs < “oo”=egg + “skopia”=to examine, look at.
oose: Fluff that comes from wool or cotton. Scots variant of “wool” < Old English “wul”=hair from an animal < Old Germanic “*wullo”
ootheca: The egg case of cockroaches, mantises, and related insects. Greek “oo-“=eggs, related to eggs + “thiki”=case, receptacle.
opaque: Dark, dim, not illuminated; unclear. Middle French “opaque” < Latin “opacus”=shaded, darkened, or mysterious.
operose: Made with, or involving, lots of effort or work; laborious and/or tedious. Latin “operosus” < “opus”=work + “-osus”=adjective-forming suffix.
ophic: Of, or relating, to snakes. Greek “ofis”=serpent, snake + “-ik”=adjective-forming suffix.
ophidian: Of, relating to, or resembling a snake or serpent; snakelike. Latin “Ophidea”=a suborder of reptiles that are snakes < Greek “ophis”=snake, serpent.
opine: To express an opinion. Middle English “opyne” < Latin “opinare”=to hold an opinion.
opinion: A view or judgement on a topic but not necessarily based on facts. Anglo-Norman “opinian” < Latin “opinare”=to think or believe.
opium: A powerful, often illegal, pain-killing drug made from poppy seeds. Latin “opium” < Greek “opion”=poppy juice < “opos”=plant juice < Proto-Indo-European “*swokwos”=juice.
oppidan: Someone who lives in a town. Latin “oppidanus” < “oppidum”=town, usually a walled town + “-anus”=suffix meaning “belonging to.”
opportune: Appropriate or suitable for a particular action. Originally a wind blowing to harbor. Latin “ob-“=toward + “portus”=harbor.
opposite: Different from something else; contrary to. From Latin “opponere”=set against < “ob-“+against + “ponere”=to place.
opprobrium: Strong criticism or disapproval, especially when expressed in public. Latin “obprobrium”=shame, disgrace < “ob-“=in the direction of + “probrum”=an insult or disgrace.
oppugn: To question the truth or validity. Latin “oppugnare”=to attack or besiege < “ob-“=against + “pugnare”=to fight.
opsigamy: Getting married later in life. Greek “opisgamous”=late-married < “opsi”=late + “gamos”=marriage.
opsomaniac: A person with an excessive craving for a specific food. Greek “opson”=rich food, delicacy + “mania”=madness.
opsophagist: Someone who eats delicacies, especially fish. Greek “opsophagos” < “opson”=rich food + “phagos”=suffix meaning “that feeds on”
optimism: Tendency to think things will turn out for the best. French “optimisme” < Latin “optimus”=best + Greek “-ism”=noun-forming suffix
opulence: Great wealth, riches, or luxury. Latin “opulentia”=wealth, splendor < “opulentus”=wealthy < “ops”=power, resources.
opulent: Exhibiting great wealth and richness. From Latin “opulentus”=wealthy.
oracle: A person/place through which gods speak to reveal the future. Latin “oraculum”=place where gods speak < “orare”=to speak.
oragious: Stormy, tempestuous. Middle French “orageux”=stormy < Old French “ore”=wind < Latin “aura” < Greek “aura”=breath, breeze.
oral: Pertaining to the mouth. A phase in psychosexual development. Latin “oralis” < “or”=mouth + “alis”=adjective-forming suffix.
orator: Skilled and eloquent public speaker. Anglo-Norman “oratour”=petitioner < Latin “orator”=speaker, advocate < “orare”=to speak.
orature: A body of poems preserved by oral transmission. Blend of “oral” (Latin “or”=mouth) and “literature” (Latin “littera”=letter).
orb: Gold globe with cross on top used as regalia by a monarch. Middle French “orbe”=sphere < Latin “orbis”=ring, circle, eyeball.
orbate: Orphaned or bereaved. Latin “orbatus”=bereaved or deprived < “orbare”=to bereave < “orbus”=childless < Greek “orfanos”=orphan.
orchard: Piece of enclosed land containing fruit trees. Old English “ortgeard” < Latin “hortus”=garden + Old English “geard”=yard, home.
orchestra: A group playing instruments, typically strings, woodwind, brass and percussion. Greek “orkestra”=place where the chorus danced.
orchid: Plant with fragrant and showy flowers. Latin “orchis” < Greek “orchis”=testicle, referring to the shape of the plant’s roots.
ordeal: A hard, painful, and/or prolonged experience. Old English “ordal” < Proto-Germanic “*uzdailijan”=to deal out or share out.
order: A state in which all things are in their correct place. Old French “ordre” < Latin “ordo”=row, series, or rank.
ordinance: An authoritative order. Old French “ordenance”=something ordered < Latin “ordinare”=to put in rows, regulate < “ordo”=order.
oread: A nymph who lives in mountains. Greek “oreios”=of the mountain < “oros”=mountain.
oregano: Aromatic Eurasian herb with small purple flowers and leaves. Latin “origanum” < Greek “origanon” < “oros”=mountain + “ganos”=bright
orgasm: Climax of sexual excitement. Latin “orgasmus”=excitement of bodily organ < Greek “orgasmos” < “organ”=to swell < Sanskit “urj”=vigor
orgeat: Cooling drink made from orangeflower water and either barley or almonds. Middle French “orgeat” < Latin “hordeum”=barley.
orgulous: Proud or haughty. Anglo-Norman “orguil”=pride + Latin “-ous”=suffix meaning “full of” or “abounding in.”
orgy: Wild party, usually of a sexual nature. Middle French “orgies” < Latin “orgia”=secret rites < Greek “orgia” <? “ergon”=to work.
oriental: Of or referring to countries in the East. Anglo-Norman “oriente”=the East < Latin “oriens”=where the sun rises < “oriri”=to rise.
orifice: An opening, such as a vent, mouth, or hole, through which something may pass. Middle French “orifice”=opening, aperture < Latin “orificium” < “ori-“=mouth + “facere”=to make.
oriflamme: An orange-red banner used by a Knight of St. Denis. Old French “oriflambe” < “or”=gold + “flambe”=flame < Latin “flamma”=flames.
origami: Japanese art of folding paper into decorative shapes or objects. Japanese “ori”=fold + “gami”=paper.
orison: A prayer; a speech. Anglo-Norman “oreison”=prayer, discourse < Latin “oration” < “orare”=to speak, plead, or pray.
ormete: Huge, immeasurable, excessive. Old English “or-“=prefix meaning “without” + “moete”=moderation, measure.
ormolu: Gold-colored mix of copper, zinc, and tin used for making ornaments. Old French “or molu”=ground gold < “or”=gold + “moudre”=to grind.
ornamental: Decorative or created for appearance and beauty. From Latin “ornamentum”=embellishment < “ornare”=to adorn or equip. #words #esl
ornate: Covered with a lot of decoration. Latin “ornatus”=richly adorned or embellished < “ornare”=to adorn.
ornery: Stubborn or bad-tempered. North American regional from of “ordinary” < Middle French “ordinaire” < Latin “ordinarius”=customary.
orotund: Used to describe a voice with fullness, strength, and clarity of sound. Latin “ore rotundo”=with open mouth < “ore”=mouth + “rotundus”=round.
orphan: A child whose parents are dead. Latin “orphanus” < Greek “orfanos”=bereaved, deprived of protection.
orrery: A clockwork model of the solar system, invented by George Graham. Eponym, named in honor of Charles Boyle, the 4th Earl of Orrery.
orthodox: Following some traditional or generally accepted rules or beliefs of a religion, philosophy, or practice. Latin “orthodoxus” < Greek “orthodoxos” < “orthos”=straight, correct, right + “doxa”=opinion.
orthopedics: A branch of medicine that deals with the correction of deformities of bones or muscles. French “orthopédie” < Greek “ortho-“=straight, correct, proper + “paideia”=child rearing < “paideuein”=to educate.
orthosis: The correction of disorders of the limbs or spine by use of braces and other devices to correct alignment or provide support. Greek “orthosis”=making straight < “orthoun”=to make straight < “othos”=straight.
oscillate: To move backward and forwards in a regular rhythm. Latin “oscillare”=to swing.
oscitation: The act of yawning. Latin “oscitatio”=the action of yawning < “oscitare”=to yawn or gape < “os”=mouth + “citare”=to move.
osculate: To kiss a person or thing. Latin “osculari”=to kiss < “osculum”=a kiss < “os”=mouth + “culum”=suffix meaning “small.”
ostensible: Represented or appearing as such; pretended; usage. Latin “ostendere”=to show < “ob”=toward + “tendere”=extend.
ostentatious: Intended to attract notice and impress others; showy. From Latin “ostentate”=to show off + “ious”=full of.
osteyour: 15th century name for a soldier. Old French “osteieor”=one who makes war < Latin “hostis”=army, warlike expedition.
ostiary: A doorkeeper, especially of a church. Latin “ostiarius” < “ostium”=door < “os”=mouth + “-arius”=suffix meaning “connected to.”
ostracize: To banish from a group. Greek “ostrakitsein”=to banish from a city < “ostrakon”=pot into which votes to banish someone were put.
ostreophagist: One who eats or feeds on oysters. Latin “ostrea”=oyster + “phagist”=one who eats < Greek “fagein”=to eat.
ostrich: Large flightless African bird with long legs and long neck, which can run very fast. Anglo-Norman “ostrige” < Latin “avis”=bird + “struthio”=sparrow < Greek “strouthos”=sparrow or ostrich.
ostroid: Resembling an oyster. Latin “ostrea”=oyster + “-oides” < Greek “-oeithis”=suffix meaning “having the form of.”
otacousticon: Device for helping hearing e.g. ear trumpet. Greek “oto”=ear + “acoustikos”=to do with hearing < “akouein”=to hear.
otacust: A spy or eavesdropper. Middle French “otacuste” < Latin “otocustes”=spy, listener < Greek “otakoustis” < “oto-“=ear + “akouein”=to hear.
otalgia: Pain in the ear; earache. Latin “otalgia” < Greek “otalgia” < “oto-“=ear + “-algia”=suffix creating nouns related to pain.
otary: Any seal with small ears i.e. sea lion or fur seal. Greek “otarian”=little ear < “oto-“=ear + “-ion”=diminutive suffix for “little.”
otenchyte: An device for injected fluid into the ear. Greek “otenkitis” < “oto-“=ear + “kein”=to pour + “-tis”=noun-forming suffix.
otiose: Unnecessary or futile; being lazy. Latin “otiosus”=ineffectual, inactive, idle < “otium”=leisure, freedom from business.
oubliette: Secret dungeon with access through a trapdoor in its ceiling. Old French “oublider”=to forget < Latin “oblivisci”=to forget.
ounce: A unit of weight of one twelfth of a pound in troy weight (about 28 grams). Middle English “untse” < Old French “unce” < Latin “uncia”=a twelfth part.
oust: To remove someone from a position of power. Anglo-Norman “ouster”=to remove, take away < Latin “obstare”=to hinder, stand in the way.
outrageous: Hard to believe. Anglo-Norman “outrageus”=excessively cruel or wrong < Old French “ultrage” < Latin “ultra”=beyond.
outré: Unusual and shocking. French “oultrer”=to go beyond the limit < Latin “ultra”=beyond or extreme.
ovation: A long and enthusiastic show of appreciation from an audience, especially by lots of applause. Latin “ovatio”=A processional entrance into Rome but less lavish than a triumph < “ovare”=to celebrate, exult.
overweening: Being too proud or confident in yourself; to have excessively or unreasonably high expectations. Old English “ofer”=above, greater/higher than + “wenan”=to think, surmise, consider.
overwrought: Deeply agitated especially with emotion. From Old English “over”=in excess + “wyrcan”=to work (“wrought”=old form).
ovicaprid: Of, relating to, or designating sheep or goats. Latin “ovis”=sheep = “capra”=she-goat + “-id”=suffix used to form a noun denoting members of a zoological group.
oviparous: Able to produce young by means of eggs that are hatched after they have been laid by the parent. Latin “oviparus” < “ova”=egg + “parus”=producing.
oxlip: A Eurasian flower similar to a cowslip or primula with yellow flowers that hang down one side of the stem. Old English “oxanslyppe” < “oxa”=ox + “slyppe”=slime, fluid.
oxygen: Colorless, odorless gas, essential for life, atomic #8. French “oxygène”=acidifying < Greek “oxi-“=sharp, acidic + “genes”=kind of.
oxymel: A medicinal drink or syrup made of vinegar and honey. Latin “oxymel” < Greek “oxus”=sharp (tasting) + “meli”=honey.
oxymoron: A pairing of words that seem to contradict each other e.g. deafening silence. Greek “oxus”=acute(ly) + “moros”=foolish.
oyster: Bi-valved shellfish eaten raw or cooked. Old French “oistre” < Greek “ostreon” < Proto-Indo-European *”ost-“=bone.