oak (n.)youdaoicibaDictYouDict[oak 词源字典]
Old English ac "oak tree," from Proto-Germanic *aiks (cognates: Old Norse eik, Old Saxon and Old Frisian ek, Middle Dutch eike, Dutch eik, Old High German eih, German Eiche), of uncertain origin with no certain cognates outside Germanic.

The usual Indo-European base for "oak" (*deru-) has become Modern English tree (n.); likewise in Greek and Celtic words for "oak" are from the Indo-European root for "tree," probably reflecting the importance of the oak to ancient Indo-Europeans. The Old Norse form was eik, but as there were no oaks in Iceland the word came to be used there for "tree" in general. Used in Biblical translations to render Hebrew elah (probably usually "terebinth tree") and four other words.[oak etymology, oak origin, 英语词源]
oaken (adj.)youdaoicibaDictYouDict
"made of, or consisting of, oak," late 12c., from oak + -en (2).
oakum (n.)youdaoicibaDictYouDict
"loose fiber obtained from taking apart old hemp ropes," early 15c., from Old English acumba "tow, oakum, flax fibers separated by combing," literally "what is combed out," from Proto-Germanic *us-kambon (source of Old High German achambi); first element cognate with Old English a- "away, out, off;" second element from stem of cemban "to comb," from camb "a comb;" from PIE *gembh- "tooth, nail" (see comb (n.)).
oar (n.)youdaoicibaDictYouDict
Old English ar "oar," from Proto-Germanic *airo (cognates: Old Norse ar, Danish aare, Swedish åra), of unknown origin; perhaps related to Latin remus "oar," Greek eretes "rower," eretmos "oar."
oarlock (n.)youdaoicibaDictYouDict
mid-14c., from oar + lock (n.1).
oasis (n.)youdaoicibaDictYouDict
1610s, from French oasis (18c.) and directly from Late Latin oasis, from Greek oasis, probably from Hamitic (compare Coptic wahe, ouahe "oasis," properly "dwelling place," from ouih "dwell"). The same Egyptian source produced Arabic wahah.
oat (n.)youdaoicibaDictYouDict
Old English ate (plural atan) "grain of the oat plant, wild oats," of uncertain origin, possibly from Old Norse eitill "nodule," denoting a single grain, of unknown origin. The English word has cognates in Frisian and some Dutch dialects. Famously defined by Johnson as, "A grain, which in England is generally given to horses, but in Scotland supports the people."

The usual Germanic name is derived from Proto-Germanic *khabran (cognates: Old Norse hafri, Dutch haver, source of haversack). Wild oats, "crop that one will regret sowing," is first attested 1560s, in reference to the folly of sowing these instead of good grain.
That wilfull and vnruly age, which lacketh rypenes and discretion, and (as wee saye) hath not sowed all theyr wyeld Oates. [Thomas Newton, "Lemnie's Touchstone of complexions," 1576]



Fred: I still want to sow some wild oats!
Lamont: At your age, you don't have no wild oats, you got shredded wheat.
["Sanford and Son"]
Hence, to feel (one's) oats "be lively," 1831, originally American English.
oater (n.)youdaoicibaDictYouDict
Western film, "horse opera," 1946, from oat, as the typical food of horses.
oath (n.)youdaoicibaDictYouDict
Old English "oath, judicial swearing, solemn appeal to deity in witness of truth or a promise," from Proto-Germanic *aithaz (cognates: Old Norse eiðr, Swedish ed, Old Saxon, Old Frisian eth, Middle Dutch eet, Dutch eed, German eid, Gothic aiþs "oath"), from PIE *oi-to- "an oath" (cognates: Old Irish oeth "oath"). Common to Celtic and Germanic, possibly a loan-word from one to the other, but the history is obscure. In reference to careless invocations of divinity, from late 12c.
oatmeal (n.)youdaoicibaDictYouDict
late 14c., from oat + Middle English mele (see meal (n.2)).
ob-youdaoicibaDictYouDict
prefix meaning "toward, against, across, down," also used as an intensive, from Latin ob "toward, to, over against, in the way of, by reason of, about, before, in front of," from PIE root *epi, also *opi "near, against" (see epi-).
ObadiahyoudaoicibaDictYouDict
masc. proper name, fourth of the Twelve Prophets of the Old Testament, from Hebrew Obhadyah, literally "servant of the Lord," from abhadh "he served, worshipped," related to Arabic 'abada "he served," 'abd "slave, worshipper."
obbligato (adj.)youdaoicibaDictYouDict
musical instruction, 1724, from Italian obbligato, literally "obligated," from Latin obligatus, past participle of obligare "to bind" (see oblige). In reference to a necessary accompaniment by a single instrument.
obduracy (n.)youdaoicibaDictYouDict
"stubbornness," 1590s, from obdurate + -cy.
obdurate (adj.)youdaoicibaDictYouDict
mid-15c., "stubborn; hardened," from Latin obduratus "hardened," past participle of obdurare "be hard, hold out, persist, endure," from ob "against" (see ob-) + durare "harden, render hard," from durus "hard" (see endure). Related: Obdurately.
obduration (n.)youdaoicibaDictYouDict
c. 1400, "hard-heartedness," from Latin obdurationem (nominative obduratio), noun of state from past participle stem of obdurare (see obdurate).
obeah (n.)youdaoicibaDictYouDict
"sorcery, witchcraft" among blacks in Africa and the W.Indies, 1760, from a West African word, such as Efik (southern Nigeria) ubio "a thing or mixture left as a charm to cause sickness or death," Twi ebayifo "witch, wizard, sorcerer."
obedience (n.)youdaoicibaDictYouDict
c. 1200, "submission to a higher power or authority," from Old French obedience "obedience, submission" (12c.) and directly from Latin oboedientia "obedience," noun of quality from oboedientem (nominative oboediens); see obedient. In reference to dog training from 1930.
obedient (adj.)youdaoicibaDictYouDict
c. 1200, from Old French obedient "obedient" (11c.), from Latin oboedientem (nominative oboediens), present participle of oboedire "to obey" (see obey). Related: Obediently.
obeisance (n.)youdaoicibaDictYouDict
late 14c., "act or fact of obeying," from Old French obeissance "obedience, service, feudal duty" (13c.), from obeissant, present participle of obeir "obey," from Latin oboedire (see obey). Sense in English altered late 14c. to "bending or prostration of the body as a gesture of submission or respect" by confusion with abaisance. Related: Obeisant.