Oscar
masc. proper name, Old English Osgar "god's spear," from gar "spear" (see gar) + os "god" (only in personal names); see Aesir.

The statuette awarded for excellence in film acting, directing, etc., given annually since, 1928, first so called 1936. The name is said to have sprung from a 1931 remark by Margaret Herrick, secretary at Academy of Motion Picture Arts and Sciences, on seeing the statuette: "He reminds me of my Uncle Oscar." Thus the award would be named for Oscar Pierce, U.S. wheat farmer and fruit grower.
oscillate (v.)
1726, back-formation from oscillation, or else from Latin oscillatus, past participle of oscillare (see oscillation). From 1917 in electronics. Related: Oscillated; oscillating.
oscillation (n.)
1650s, from French oscillation, from Latin oscillationem (nominative oscillatio), noun of action from past participle stem of oscillare "to swing," supposed to be from oscillum "little face," literally "little mouth," a mask of open-mouthed Bacchus hung up in vineyards as a charm (the sense evolution would be via the notion of "swing in the breeze"); from PIE *os- "mouth" (see oral).
oscillator (n.)
agent noun in Latin form from oscillate; 1835 of persons, 1889 in reference to electric currents.
oscilloscope (n.)
"instrument for visually recording an electrical wave," 1915, a hybrid formed from Latin oscillare "to swing" (see oscillation) + -scope.
oscitant (adj.)
"yawning," from Latin oscitans "listless, sluggish, lazy," present participle of oscitare "to gape, yawn," from os citare "to move the mouth" (see oral and cite).
oscitation (n.)
1540s, from Late Latin oscitationem (nominative oscitatio), noun of action from past participle stem of oscitare (see oscitant).
osculate (v.)
"to kiss," 1650s, from Latin osculatus, past participle of osculari "to kiss," from osculum "a kiss; pretty mouth, sweet mouth," literally "little mouth," diminutive of os "mouth" (see oral). Related: Osculated; osculating.
osculation (n.)
"kissing; a kiss," 1650s, from Latin osculationem (nominative osculatio), noun of action from past participle stem of osculari (see osculate).
osier (n.)
species of willow used in basket-work, c. 1300, from Old French osier "willow twig" (13c.) and directly from Medieval Latin osera "willow," ausaria "willow bed," of unknown origin, perhaps from Gaulish. Old English had the word as oser, from Medieval Latin.
Osiris
name of a principal god of Egypt, judge of the dead, from Latin Osiris, from Greek, from Egyptian Asar. Related: Osirian.
Oslo
Norwegian capital, probably based on Old Norse os "estuary, river mouth," based on the place's situation.
Osmanli
"an Ottoman Turk," 1813, from Turkish Osmanli "of or pertaining to Osman," founder of the Ottoman dynasty (he reigned 1259-1326); his name is the Turkish pronunciation of Arabic Uthman. This is the native word where English generally uses Ottoman.
osmium (n.)
metallic element, 1803, coined in Modern Latin by its discoverer, English chemist Smithson Tennant (1761-1815) from Greek osme "smell, scent, odor" good or bad, from PIE root *od- (1) "to smell" (see odor). With metallic element ending -ium. So called for the strong smell of its oxide.
Osmond
masc. proper name, from Old English Osmund, literally "divine protection," from os "a god" (see Oscar) + -mund (see mount (n.1)).
osmosis (n.)
1867, Latinized from osmose (1854), shortened from endosmosis (1830s), from endosmose "inward passage of a fluid through a porous septum" (1829), from French endo- "inward" + Greek osmos "a thrusting, a pushing," from stem of othein "to push, to thrust," from PIE *wedhe- "to push, strike" (source also of Sanskrit vadhati "pushes, strikes, destroys," Avestan vadaya- "to repulse"). Figurative sense is from 1900. Related: Osmotic (1854, from earlier endosmotic).
osprey (n.)
fishing hawk, mid-15c., from Anglo-French ospriet, from Medieval Latin avis prede "bird of prey," from Latin avis praedæ, a generic term apparently confused with this specific bird in Old French on its similarity to ossifrage.
osseous (adj.)
"bony," early 15c., from Medieval Latin ossous, from Latin osseus "bony, of bone," from os (genitive ossis) "bone," from PIE root *ost- "bone." The word later was reformed in English (1680s), perhaps by influence of French osseux.
Ossianic (adj.)
1808, in reference to Oisin, name of a legendary Gaelic bard, literally "little fawn;" James Macpherson claimed to have collected and translated his works (1760-1763) under the name Ossian, and the poetic prose sparked a Celtic revival and fascination with the glamor of the lost world of the bards. The work turned out to be Macpherson's forgery, and the style later was regarded as bombastic, but the resulting swerve in European literature was real.
ossicle (n.)
1570s, from Latin ossiculum, diminutive of os "bone" (from PIE root *ost- "bone").
ossification (n.)
1690s, from Latin ossis "of bones," genitive of os "bone" (from PIE root *ost- "bone") + -fication "a making or causing."
ossifrage (n.)
"sea-eagle, osprey," c. 1600, from Latin ossifraga "vulture," fem. of ossifragus, literally "bone-breaker," from ossifragus (adj.) "bone-breaking," from os (genitive ossis) "bone" (from PIE root *ost- "bone") + stem of frangere "to break" (from PIE root *bhreg- "to break"). By this name Pliny meant the lammergeier (from German, literally "lamb-vulture"), a very large Old World vulture that swallows and digests bones and was believed also to drop them from aloft to break them and get at the marrow. But in England and France, the word was transferred to the osprey, perhaps on similarity of sound between the two words.
ossify (v.)
1713, "to turn into bone," a back-formation from ossification, or else modeled on French ossifier (18c.) and formed from Latin os (genitive ossis) "bone" (from PIE root *ost- "bone") + -fy. Figurative sense is from 1858. Related: Ossified; ossifying.
ossuary (n.)
"urn for the bones of the dead," 1650s, from Late Latin ossuarium "charnel house," from neuter of Latin ossuarius "of bones," from Latin os (plural ossua) "bone" (from PIE root *ost- "bone") on model of mortuarium.
ostensible (adj.)
1762, "capable of being shown, presentable," from French ostensible, from Latin ostens-, past participle stem of ostendere "to show, expose to view; to stretch out, spread before; exhibit, display," from ob "in front of" (see ob-) + tendere "to stretch," from PIE root *ten- "to stretch." Meaning "apparent, professed" is from 1771.
ostensibly (adv.)
1765, from ostensible + -ly (2).
ostensive (adj.)
c. 1600, from Late Latin ostensivus "showing," from Latin ostensus, past participle of ostendere "to show" (see ostensible).
ostentation (n.)
mid-15c., from Old French ostentacion (mid-14c.) and directly from Latin ostentationem (nominative ostentatio) "showing, exhibition, vain display," noun of action from past participle stem of ostentare "to display," frequentative of ostendere "to show" (see ostensible).
ostentatious (adj.)
1701, from ostentation + -ous. Earlier in a similar sense were ostentative (c. 1600); ostentive (1590s). Related: Ostentatiously; ostentatiousness (1650s).
osteo-
before vowels oste-, word-forming element meaning "bone, bones," from Greek osteon "bone," from PIE root *ost- "bone."
osteology (n.)
1660s, from French ostèologie, from Modern Latin osteologia, from Greek osteon "bone" (from PIE root *ost- "bone") + -logia (see -logy).
osteopath (n.)
1897, back-formation from osteopathy.
osteopathy (n.)
1857, "disease of the bones," from Greek osteon "bone" (from PIE root *ost- "bone") + -pathy, from Greek -patheia, combining form of pathos "suffering, disease, feeling" (from PIE root *kwent(h)- "to suffer"). As a system of treating ailments by the manipulation of bones, it dates from 1889.
osteoporosis (n.)
1846, from osteo- + stem of Greek poros "passage, pore, voyage" (see pore (n.)) + -osis. Related: Osteoporotic.
ostinato
1876, from Italian ostinato "obstinate, persistent."
ostler (n.)
late 14c., phonetic spelling of hostler.
ostomy (n.)
1957, abstracted from colostomy, etc.; ultimately from Modern Latin stoma "opening, orifice," from Greek stoma "mouth" (see stoma).
ostracise (v.)
chiefly British English spelling of ostracize (q.v.); for suffix, see -ize. Related: Ostracised.
ostracism (n.)
1580s, a method of 10-year banishment in ancient Athens, by which the citizens gathered and each wrote on a potsherd or tile the name of a man they deemed dangerous to the liberties of the people, and a man whose name turned up often enough was sent away. From Middle French ostracisme (16c.), Modern Latin ostracismus, or directly from Greek ostrakismos, from ostrakizein "to ostracize," from ostrakon "tile, potsherd," from PIE *ost-r-, from root *ost- "bone," which alos is the source of Greek osteon "bone," ostreion "oyster," and German Estrich "pavement" (which is from Medieval Latin astracus "pavement," ultimately from Greek ostrakon).

A similar practice in ancient Syracuse (with banishment for five years) was by writing names on olive leaves, and thus was called petalismos.
ostracize (v.)
1640s, from Greek ostrakizein "to banish," literally "to banish by voting with potshards" (see ostracism). Figurative sense of "to exclude from society" is attested from 1640s. Related: Ostracization; ostracized; ostracizing.
ostrich (n.)
early 13c., from Old French ostruce "ostrich" (Modern French autruche) and Medieval Latin ostrica, ostrigius, all from Vulgar Latin avis struthio, from Latin avis "bird" (see aviary) + Late Latin struthio "ostrich," from Greek strouthion "ostrich," from strouthos megale "big sparrow," perhaps from PIE *trozdo- "thrush" (see thrush (n.1)). The Greeks also knew the bird as strouthokamelos "camel-sparrow," for its long neck. Among its proverbial peculiarities are indiscriminate voracity (especially a habit of swallowing iron and stone to aid digestion), want of regard for its eggs, and a tendency to hide its head when pursued.
Like the Austridge, who hiding her little head, supposeth her great body obscured. [1623, recorded in OED]
Ostriches do put their heads in the sand, but ostrich farmers say they do this in search of something to eat.
Ostrogoth (n.)
c. 1600, one of the "East Goths," who conquered Italy late 5c. and established, under Theodric, a kingdom there that lasted from 493 to 555 C.E., from Late Latin Ostrogothæ, from Germanic, perhaps literally "eastern Goths" from Proto-Germanic *austra- "east" (from PIE root *aus- (1) "to shine," on the notion of "toward sunrise"), but according to Klein's sources the first element might be literal: "shining" or "splendid." For second element, see Goth, and compare Visigoth.
Oswald
masc. proper name, from Old English Osweald "god-power, god-ruler," from Old English os "god" (only in personal names), from PIE *ansu- "spirit" (see Oscar) + Old English (ge)weald "power."
otalgia (n.)
1650s, from Greek otalgia "earache," from ous, aus (genitive otos) "ear" (see ear (n.1)) + algia "pain" (see -algia).
other (adj.)
Old English oþer "the second" (adj.), also as a pronoun, "one of the two, other," from Proto-Germanic *antharaz (source also of Old Saxon athar, Old Frisian other, Old Norse annarr, Middle Dutch and Dutch ander, Old High German andar, German ander, Gothic anþar "other").

These are from PIE *an-tero-, variant of *al-tero- "the other of two" (source of Lithuanian antras, Sanskrit antarah "other, foreign," Latin alter), from root *al- (1) "beyond" + adjectival comparative suffix *-tero-. The Old English, Old Saxon, and Old Frisian forms show "a normal loss of n before fricatives" [Barnhart]. Meaning "different" is mid-13c.

Sense of "second" was detached from this word in English (which uses second, from Latin) and German (zweiter, from zwei "two") to avoid ambiguity. In Scandinavian, however, the second floor is still the "other" floor (Swedish andra, Danish anden). Also compare Old English oþergeara "next year."

The other woman "a woman with whom a man begins a love affair while he is already committed" is from 1855. The other day originally (mid-12c.) was "the next day;" later (c. 1300) "yesterday;" and now, loosely, "a day or two ago" (early 15c.). Phrase other half in reference to either the poor or the rich, is recorded from c. 1600.
La moitié du monde ne sçayt comment l'aultre vit. [Rabelais, "Pantagruel," 1532]
otherness (n.)
1580s, from other + -ness.
otherwise (adv.)
contracted from Old English phrase on oðre wisan "in the other manner" (see other + wise (n.)), which in Middle English became oþre wise, and mid-14c. oþerwise. As an adjective from c. 1400.
otherworldly (adj.)
1854, from other + world + -ly (1). Otherworldliness is recorded from 1819. Phrase other world "world of idealism or fantasy, afterlife, spirit-land" is c. 1200.
otic (adj.)
"pertaining to the ear," from Greek otikos, from ous (genitive otos) "ear" (see ear (n.1)).
otiose (adj.)
1794, "unfruitful, futile," from Latin otiosus "having leisure or ease, unoccupied, idle, not busy" (source of French oiseux, Spanish ocioso, Italian otioso), from otium "leisure, free time, freedom from business," of unknown origin. Meaning "at leisure, idle" is recorded from 1850. Compare Latin phrase otium cum dignitate "leisure with dignity." Earlier adjective in English was otious- "at ease" (1610s), and Middle English had noun otiosity (late 15c.).