Online Etymology Dictionary

obese (adj.): 1650s, back-formation from obesity and in part from Latin obesus "fat, stout, plump," past participle of obedere "that has eaten itself fat" (see obesity). According to OED, "Rare before 19th c." Related: Obeseness. Latin obesus was translated in Old English as oferfæt "overfat."
obesity (n.): 1610s, from French obésité and directly from Latin obesitas "fatness, corpulence," from obesus "that has eaten itself fat," past participle of obdere "to eat all over, devour," from ob "over" (see ob-) + edere "eat" (see edible).
obey (v.): late 13c., from Old French obeir "obey, be obedient, do one's duty" (12c.), from Latin obedire, oboedire "obey, be subject, serve; pay attention to, give ear," literally "listen to," from ob "to" (see ob-) + audire "listen, hear" (see audience). Same sense development is in cognate Old English hiersumnian. Related: Obeyed; obeying.
obfuscate (v.): 1530s, from Latin obfuscatus, past participle of obfuscare "to darken," from ob "over" (see ob-) + fuscare "to make dark," from fuscus "dark" (see dusk). Related: Obfuscated; obfuscating.
obfuscation (n.): early 15c., originally medical, "the darkening of a sore," from Latin obfuscationem (nominative obfuscatio), noun of action from past participle stem of obfuscare (see obfuscate).
Obie: one of the annual awards given to off-Broadway theater, 1967, from O.B. as the abbreviation of Off-Broadway.
obit (n.): late 14c., "death," from Middle French obit or directly from Latin obitus "death," noun use of past participle of obire "to die," literally "to go toward" (see obituary). In modern usage (since 1874) it is usually a clipped form of obituary, though it had the same meaning of "published death notice" 15c.-17c. The scholarly abbreviation ob. with date is from Latin obiit "(he) died," third person singular of obire.
obiter (adv.): Latin, literally "by the way," from ob "to, toward" (see ob-) + iter "journey" (see ion). Klein's sources, however, say it is ob- with the suffix -iter in analogy of circiter "about" from circa. Also cf. obituary.
obiter dictum: "statement in passing," a judge's expression of opinion not regarded as binding or decisive, Latin, literally "something said incidentally;" see obiter + dictum.
obituary (n.): 1706, "register of deaths," from Medieval Latin obituarius "a record of the death of a person," literally "pertaining to death," from Latin obitus "departure, a going to meet, encounter" (a euphemism for "death"), from stem of obire "go toward, go to meet" (as in mortem obire "meet death"), from ob "to, toward" (see ob-) + ire "to go" (see ion). Meaning "record or announcement of a death, especially in a newspaper, and including a brief biographical sketch" is from 1738. As an adjective from 1828. A similar euphemism is in Old English cognate forðfaran "to die," literally "to go forth;" utsið "death," literally "going out, departure."
object (n.): late 14c., "tangible thing, something perceived or presented to the senses," from Medieval Latin objectum "thing put before" (the mind or sight), noun use of neuter of Latin obiectus "lying before, opposite" (as a noun in classical Latin, "charges, accusations"), past participle of obicere "to present, oppose, cast in the way of," from ob "against" (see ob-) + iacere "to throw" (see jet (v.)). Sense of "thing aimed at" is late 14c. No object "not a thing regarded as important" is from 1782. As an adjective, "presented to the senses," from late 14c. Object lesson "instruction conveyed by examination of a material object" is from 1831.
object (v.): c.1400, "to bring forward in opposition," from Old French objecter and directly from Latin obiectus, past participle of obiectare "to cite as grounds for disapproval, set against, oppose," literally "to put or throw before or against," frequentative of obicere (see object (n.)). Related: Objected; objecting.
objectification (n.): 1860, noun of action from objectify.
objectify (v.): 1838, from Medieval Latin objectum (see object (n.)) + -fy. Related: Objectified; objectifying.
objection (n.): late 14c., from Old French objeccion "reply, retort" (12c.) and directly from Late Latin obiectionem (nominative obiectio), "a throwing or putting before," noun of action from past participle stem of Latin obicere "to oppose" (see object (n.)).
objectionable (adj.): 1781, from objection + -able. Related: Objectionably.
objective (adj.): 1610s, originally in the philosophical sense of "considered in relation to its object" (opposite of subjective), formed on pattern of Medieval Latin objectivus, from objectum "object" (see object (n.)) + -ive. Meaning "impersonal, unbiased" is first found 1855, influenced by German objektiv. Related: Objectively.
objective (n.): 1738, "something objective to the mind," from objective (adj.). Meaning "goal, aim" (1881) is from military term objective point (1852), reflecting a sense evolution in French.
objectivism (n.): 1854 in philosophical sense, "the doctrine that knowledge is based on objective reality," from objective (adj.) + -ism.
objectivity (n.): 1803, from Medieval Latin objectivus, from Latin objectus (see object (n.)) + -ity.
objet (n.): "an object on display, an ornament," 1857, from French objet (14c.), especially in objet d'art (1865), from Latin objectus (see object (n.)).
objurgate (v.): 1610s, from Latin obiurgatus, past participle of obiurgare "to chide, rebuke," from ob- (see ob-) + iurgare "to quarrel, scold," from phrase iure agere "to deal in a lawsuit," from ablative of ius "right; law; suit" (see just (adj.)) + agere "to do, act, set in motion" (see act (n.)). Related: Objurgatory.
objurgation (n.): 1540s, from Latin obiurgationem (nominative obiurgatio) "a chiding, reproving, reproof," noun of action from past participle stem of obiurgare (see objurgate).
oblate (adj.): "flattened on the ends," 1705, from Medieval Latin oblatus "flattened," from Latin ob "toward" (see ob-) + latus, abstracted from its opposite, prolatus "lengthened" (see oblate (n.)).
oblate (n.): "person devoted to religious work," 1756, from Medieval Latin oblatus, noun use of Latin oblatus, variant past participle of offerre "to offer, to bring before," from ob- (see ob-) + latus "carried, borne" (used as suppletive past participle of ferre "to bear"), from *tlatos, from PIE root *tel-, *tol- "to bear, carry" (see extol).
oblation (n.): early 15c., from Old French oblacion "offering, pious donation" and directly from Latin oblationem (nominative oblatio) "an offering, presenting, gift," in Late Latin "sacrifice," from Latin oblatus (see oblate (n.)).
obligate (v.): 1540s, "to bind, connect;" 1660s, "to put under moral obligation," back-formation from obligation, or else from Latin obligatus, past participle of obligare (see oblige). Oblige, with which it has been confused since late 17c., means "to do one a favor." Related: Obligated; obligating.
obligation (n.): c.1300, from Old French obligacion "obligation, duty, responsibility" (early 13c.) and directly from Latin obligationem (nominative obligatio) "an engaging or pledging," literally "a binding" (but rarely used in this sense), noun of action from past participle stem of obligare (see oblige). The notion is of binding with promises or by law or duty.
obligatory (adj.): c.1400, from Old French obligatoire "creating an obligation, obligatory," and directly from Late Latin obligatorius "binding," from obligat-, past participle stem of obligare (see oblige).
oblige (v.): c.1300, "to bind by oath," from Old French obligier "engage one's faith, commit (oneself), pledge" (13c.), from Latin obligare "to bind, bind up, bandage," figuratively "put under obligation," from ob "to" (see ob-) + ligare "to bind," from PIE root *leig- "to bind" (see ligament). Main modern meaning "to make (someone) indebted by conferring a benefit or kindness" is from 1560s. Related: obliged; obliging.
obliged (adj.): c.1600, past participle adjective from oblige. To be obliged "be bound by ties of gratitude" is from 1540s.
obligee (n.): "person to whom another is bound by contract," 1570s, from oblige + -ee.
obliging (adj.): "willing to do service or favors," 1630s, present participle adjective from oblige. Related: Obligingly.
obligor (n.): "person who binds himself to another by contract," 1540s, agent noun in Latin form from oblige.
oblique (adj.): early 15c., from Middle French oblique (14c.) and directly from Latin obliquus "slanting, sidelong, indirect," from ob "against" (see ob-) + root of licinus "bent upward," from PIE root *lei- "to bend, be movable" (see limb (n.1)). As a type of muscles, in reference to the axis of the body, 1610s (adj.), 1800 (n.). Related: Obliquely; obliqueness.
obliquity (n.): early 15c., from Middle French obliquité (14c.), from Latin obliquitatem (nominative obliquitas) "slanting direction, obliquity," noun of quality from obliquus (see oblique).
obliterate (v.): c.1600, from Latin obliteratus, past participle of obliterare "cause to disappear, blot out, erase, efface," figuratively "cause to be forgotten," from ob "against" (see ob-) + littera (also litera) "letter, script" (see letter (n.)); abstracted from phrase literas scribere "write across letters, strike out letters." Related: Obliterated; obliterating.
obliteration (n.): 1650s, from Late Latin obliterationem (nominative obliteratio), noun of action from past participle stem of obliterare (see obliterate).
obliviate (v.): 1660s, from Latin oblivium (see oblivion). Related: Obliviated; obliviating.
oblivion (n.): late 14c., "state or fact of forgetting," from Old French oblivion (13c.) and directly from Latin oblivionem (nominative oblivio) "forgetfulness; a being forgotten," from oblivisci (past participle oblitus) "forget," originally "even out, smooth over, efface," from ob "over" (see ob-) + root of levis "smooth," from PIE *lei-w-, from root *(s)lei- "slime, slimy, sticky" (see slime (n.)). Meaning "state of being forgotten" is early 15c.
oblivious (adj.): mid-15c., from Latin obliviosus "forgetful, that easily forgets; producing forgetfulness," from oblivion (see oblivion). Meaning "unaware, unconscious (of something)" is from 1862, formerly regarded as erroneous, this is now the general meaning and the word has lost its original sense of "no longer aware or mindful." Properly should be used with to, not of. Related: Obliviously; obliviousness.
oblong (adj.): early 15c., from Latin oblongus "more long than broad," originally "somewhat long," from ob "to, toward," here perhaps intensive (see ob-) + longus "long" (see long (adj.)). As a noun from c.1600.
obloquy (n.): mid-15c., "evil speaking," from Late Latin obloquium "speaking against, contradiction," from Latin obloqui "to speak against, contradict," from ob "against" (see ob-) + loqui "to speak," from PIE *tolkw-/*tlokw- "to speak" (see locution). Related: Obloquious.
obnoxious (adj.): 1580s, "subject to the authority of another," from Latin obnoxiosus "hurtful, injurious," from obnoxius "subject, exposed to harm," from ob "to, toward" (see ob-) + noxa "injury, hurt, damage entailing liability" (see noxious). Meaning "subject to something harmful" is 1590s; meaning "offensive, hateful" is first recorded 1670s, influenced by noxious.
Obnoxious has two very different senses, one of which (exposed or open or liable to attack or injury) requires notice because its currency is now so restricted that it is puzzling to the uninstructed. It is the word's rightful or de jure meaning, and we may hope that scholarly writers will keep it alive. [Fowler]
Related: Obnoxiously; obnoxiousness.
obnubilate (v.): 1580s, from Latin obnibulatus, past participle of obnubilare "to cover with clouds or fog," from ob- (see ob-) + verb from Latin nubes "cloud" (see nuance). Related: Obnubilated; obnubilating; obnubilation.
obo: also o.b.o., abbreviation of or best offer, by 1969.
oboe (n.): 1724, from Italian oboe, from phonetic spelling of Middle French hautbois (itself borrowed in English 16c. as hautboy), from haut "high, loud, high-pitched" (see haught) + bois "wood" (see bush (n.)). So called because it had the highest register among woodwind instruments. Related: Oboist.
obol (n.): ancient Greek small coin and weight, 1660s, from Latin obolus, from Greek obolos, identical with obelos "a spit, needle." From the original shape.
obscene (adj.): 1590s, "offensive to the senses, or to taste and refinement," from Middle French obscène (16c.), from Latin obscenus "offensive," especially to modesty, originally "boding ill, inauspicious," of unknown origin; perhaps from ob "onto" (see ob-) + caenum "filth." Meaning "offensive to modesty or decency" is attested from 1590s. Legally, in U.S., it hinged on "whether to the average person, applying contemporary community standards, the dominant theme of the material taken as a whole appeals to a prurient interest." [Justice William Brennan, "Roth v. United States," June 24, 1957]; refined in 1973 by "Miller v. California":
The basic guidelines for the trier of fact must be: (a) whether 'the average person, applying contemporary community standards' would find that the work, taken as a whole, appeals to the prurient interest, (b) whether the work depicts or describes, in a patently offensive way, sexual conduct specifically defined by the applicable state law; and (c) whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value.
Related: Obscenely.
obscenity (n.): 1580s, "obscene quality," from French obscénité, from Latin obscenitatem (nominative obscenitas) "inauspiciousness, filthiness," from obscenus "offensive" (see obscene). Meaning "a foul or loathsome act" is 1610s. Sense of "an obscene utterance or word" is attested by 1690. Related: Obscenities.