obtuse (adj.)youdaoicibaDictYouDict[obtuse 词源字典]
early 15c., "dull, blunted," from Middle French obtus (fem. obtuse), from Latin obtusus "blunted, dull," also used figuratively, past participle of obtundere "to beat against, make dull," from ob "against" (see ob-) + tundere "to beat," from PIE *(s)tud-e- "to beat, strike, push, thrust," from root *(s)teu- "to push, stick, knock, beat" (cognates: Latin tudes "hammer," Sanskrit tudati "he thrusts"). Sense of "stupid" is first found c. 1500. Related: Obtusely; obtuseness.[obtuse etymology, obtuse origin, 英语词源]
obverse (adj.)youdaoicibaDictYouDict
"turned toward the observer, frontal," 1650s, from Latin obversus "turned against, directed toward," past participle of obvertere "to turn toward or against," from ob "toward" (see ob-) + vertere "to turn" (see versus). According to OED, not in common use until the end of the 18th century. The noun, in reference to coins, medals, etc. (opposite of reverse), is attested from 1650s. Related: Obversely.
obviate (v.)youdaoicibaDictYouDict
1590s, "to meet and do away with," from Late Latin obviatus, past participle of obviare "act contrary to, go against," from Latin obvius "that is in the way, that moves against" (see obvious). Related: Obviated; obviating.
obviation (n.)youdaoicibaDictYouDict
early 15c., from Medieval Latin obviationem (nominative obviatio), noun of action from past participle stem of obviare (see obviate).
obvious (adj.)youdaoicibaDictYouDict
1580s, "frequently met with," from Latin obvius "that is in the way, presenting itself readily, open, exposed, commonplace," from obviam (adv.) "in the way," from ob "against" (see ob-) + viam, accusative of via "way" (see via). Meaning "plain to see, evident" is first recorded 1630s. Related: Obviously; obviousness.
oc-youdaoicibaDictYouDict
assimilated form of ob- before -c-.
ocarina (n.)youdaoicibaDictYouDict
1877, from Italian ocarina, diminutive of oca "goose" (so called for its shape), from Vulgar Latin *auca, from Latin avicula "small bird," diminutive of avis "bird" (see aviary).
Occam's razoryoudaoicibaDictYouDict
when two competing hypotheses explain the data equally well, choose the simpler. Or, as Sir William Hamilton puts it, "Neither more, nor more onerous, causes are to be assumed, than are necessary to account for the phenomena." Named for English philosopher William of Ockham or Occam (c. 1285-c. 1349), who expressed it with Entia non sunt multiplicanda praeter ncccssitatem.
So called after William of Occam (died about 1349): but, as a historical fact, Occam does not make much use of this principle, which belongs rather to the contemporary nominalist William Durand de St. Pourçain (died 1332). [Century Dictionary]
occasion (n.)youdaoicibaDictYouDict
late 14c., "opportunity; grounds for action, state of affairs that makes something else possible; a happening, occurrence," from Old French ochaison, ocasion "cause, reason, excuse, pretext; opportunity" (13c.) or directly from Latin occasionem (nominative occasio) "opportunity, appropriate time," in Late Latin "cause," from occasum, occasus, past participle of occidere "fall down, go down," from ob "down, away" (see ob-) + cadere "to fall" (see case (n.1)). The notion is of a "falling together," or juncture, of circumstances.
occasion (v.)youdaoicibaDictYouDict
mid-15c., "to bring (something) about," from occasion (n.), or else from Old French occasionner "to cause," from Medieval Latin occasionare, from Latin occasionem (see occasion (n.)). Related: Occasioned; occasioning.
occasional (adj.)youdaoicibaDictYouDict
late 14c., "occurring now and then," from occasion (n.) + -al (1). Meaning "casual" is 1560s. Meaning "happening on or pertaining to a particular occasion" is from 1630s. Of furniture, etc., from 1749.
occasionally (adv.)youdaoicibaDictYouDict
c. 1400, "happening on some particular occasion," also "sometimes, happening as occasion presents itself, without regularity," from occasional + -ly (2).
Occident (n.)youdaoicibaDictYouDict
late 14c., "western part" (of the heavens or earth), from Old French occident (12c.) or directly from Latin occidentem (nominative occidens) "western sky, sunset, part of the sky in which the sun sets," noun use of adjective meaning "setting," from present participle of occidere "fall down, go down" (see occasion (n.)).
occidental (adj.)youdaoicibaDictYouDict
c. 1400, from Old French occidental (14c.) and directly from Latin occidentalis "western," from occidentem (see occident). As a capitalized noun meaning "a Western person" (opposed to Oriental) from 1857.
occipital (adj.)youdaoicibaDictYouDict
1540s, from Middle French occipital, from Medieval Latin occipitalis, from Latin occiput (genitive occipitis) "back of the skull," from ob "against, behind" (see ob-) + caput "head" (see capitulum).
Occitan (n.)youdaoicibaDictYouDict
"Old or modern Provençal; langue d'Oc," 1940, also "the northern variant of modern Provençal;" from French oc (see Languedoc).
occlude (v.)youdaoicibaDictYouDict
1590s, from Latin occludere (past participle occlusus) "shut up, close up," from ob "against, up" (see ob-) + claudere "to shut, close" (see close (v.)). Of teeth, 1888 (also see occlusion). Related: Occluded; occluding.
occlusion (n.)youdaoicibaDictYouDict
1640s, from Medieval Latin occlusionem (nominative occlusio), noun of action from past participle stem of Latin occludere (see occlude). Dentistry sense is from 1880.
occlusive (adj.)youdaoicibaDictYouDict
1867, from Latin occlus-, past participle stem of occludere (see occlude) + -ive.
occult (adj.)youdaoicibaDictYouDict
1530s, "secret, not divulged," from Middle French occulte and directly from Latin occultus "hidden, concealed, secret," past participle of occulere "cover over, conceal," from ob "over" (see ob-) + a verb related to celare "to hide," from PIE root *kel- (2) "to cover, conceal" (see cell). Meaning "not apprehended by the mind, beyond the range of understanding" is from 1540s. The association with the supernatural sciences (magic, alchemy, astrology, etc.) dates from 1630s.