"O" Word Origins

obtrusive

Origin

PIE word *h₁epi From Latin obtrūsus + English -ive (suffix meaning ‘of the nature of’, forming adjectives). Obtrūsus is the perfect passive participle of obtrūdō, a variant of obstrūdō (“to push, shove, or thrust against or into”), from ob- (prefix meaning ‘against; towards’) + trūdō (“to push, shove, or thrust”) (ultimately from Proto-Indo-European *trewd- (“to push; to thrust”)).

obturate

Origin

Borrowed from Latin obtūrātus, perfect passive participle of obtūrō, see -ate (verb-forming suffix) and -ate (adjective-forming suffix).

obtuse

Latin

From Latin obtusus, "blunt, dull", past participle of obtundere, "to beat against, blunt" — from ob- plus tundere, "to strike".

obverse

Origin

From Latin obversus, 1650s.

obviate

Origin

First attested in 1567; borrowed from Latin obviātus, perfect passive participle of obviō (“to block, to hinder”), see -ate (verb-forming suffix).

obvious

Latin

From Latin obvius, "in the way, easy to meet", from ob- ("towards") plus via ("road, way") — something literally "in your path" is easy to spot.

occasion

Latin

From Latin occasio, "opportunity, occurrence", from occidere, "to fall down, happen" — from ob- plus cadere ("to fall").

occasional

Origin

From "occasion" plus the adjective suffix "-al".

occasionally

Middle English

From Middle English occasionally, occasionaly, occasyoneely, occasyonly, equivalent to occasional + -ly.

occipital

Medieval Latin

From Medieval Latin occipitalis, from occiput, "back of the head" — from ob- ("against, behind") plus caput ("head").

occlude

Origin

Borrowed from Latin occlūdere, from ob (“before”) and claudere (“to shut”).

occlusion

Origin

Borrowed from Late Latin occlūsiō, occlūsiōnis (“occluding, obstruction”), from the Classical Latin occlūdō (“to shut up or close up; to restrain”), from ob + claudō (“to shut or close”).

occult

Latin

From Latin occultus, "hidden, secret", past participle of occulere, related to celare, "to hide" — the same root as "conceal".

occupancy

Origin

From "occupant" plus the noun-forming suffix "-cy".

occupant

Latin

From Latin occupans, present participle of occupare, "to seize, take possession of".

occupation

Latin

From Latin occupatio, "a seizing, taking possession", from occupare — see "occupy".

occupational

Origin

From "occupation" plus the adjective suffix "-al".

occupationless

Origin

From occupation + -less.

occupier

Origin

From Middle English occupier, occupiour, from occupien + -er (equivalent to occupy + -er) or Middle French occupier, occupiour.

occupy

Latin

From Latin occupare, "to seize, take possession of", from ob- plus capere ("to take, seize") — the same root behind "capture".

occur

Latin

From Latin occurrere, "to run to meet, present itself", from ob- ("against") plus currere ("to run").

occurred

Latin

From Latin occurrere, 'to run towards, present itself', from ob-, 'towards', and currere, 'to run'.

occurrence

Origin

From "occur" plus the noun-forming suffix "-ence".

occurrent

Origin

Borrowed from Middle French occurrent and its source, Latin occurrēns.

ocean

Latin

From Old French occean, from Latin Oceanus, from Greek Okeanos, the name of a primordial sea god who was believed to encircle the world.

oceanarium

Origin

From ocean + -arium, by analogy with aquarium.

oceanic

Latin

From Latin oceanicus, from Oceanus — see "ocean".

ocellated

Origin

Latin ocellatus, from ocellus (“a little eye”).

och

Germanic

A very old exclamation shared across the Gaelic and Scots languages, related to similar sighs like "ach" and "ouch" found in other Germanic and Celtic tongues.

Ochoa

Origin

From Basque otsoa/otxoa, meaning "wolf."

ochre

Origin

From Old French ocre and its source Latin ōchra, from Ancient Greek ὤχρα (ṓkhra, “pale yellow”), from ὠχρός (ōkhrós, “pale, ocher”) (modern Greek ωχρός (ochrós)).

ock

Arabic

Believed to come from the Arabic word for "brother", carried into New York street slang.

octad

Origin

From oct- + -ad.

octagon

Greek

From Greek okto- ("eight") plus -gonon ("angled"), the same building blocks found in "pentagon" and "hexagon".

octangular

Origin

From Classical Latin octangulus + -ar. Compare French octangulaire. By surface analysis, oct- + -angular.

octant

Origin

From Latin octāns. Doublet of Octans.

octathlon

Origin

From octa- + -athlon.

octave

Latin

From Latin octavus, "eighth" — the same root that gives us "October" and "octet".

Octavia

Latin

From Latin Octāvia, feminine of Octāvius, from octavus ("eighth").

Octavian

Latin

From Latin Octavianus, a derivative of Octāvius.

Octavius

Latin

From Latin Octāvius, the name of a Roman gens.

octavo

Origin

From Latin octavo. Doublet of octave, oitava, and ochava.

octet

Origin

From oct- (“eight”) + -et.

October

Latin

From Latin octo, "eight" — October was originally the eighth month in the old Roman calendar, before January and February were added to the front.

octoberfest

Origin

From October + -fest, after German Oktoberfest.

octocentenary

Origin

From octo- + centenary.

octonary

Origin

From the Latin octōnārius (“containing eight”), from octōnī (“eight at a time”, “by eights”, “eight each”) + -ārius (whence the English suffix -ary). Doublet of octonarius.

octopus

Greek

From Greek oktopous, literally "eight-foot", from okto ("eight") + pous ("foot").