"elongated, having one principal axis considerably longer than the others," early 15c., from Latin oblongus "more long than broad," originally "somewhat long," from ob "in front of; towards" here perhaps intensive (see ob-) + longus "long" (see long (adj.)). As a noun, "an oblong figure," from c. 1600.
"a keeping silent, a becoming willfully mute or obstinately speechless," 1640s, from Late Latin obmutescere "to become dumb or mute," from ob "against, before," here perhaps intensive (see ob-) + mutescere "to grow dumb," an inchoative verb formed from mutus "silent, speechless, dumb" (see mute (adj.)).
1580s, "subject to the authority of another" (a sense now obsolete), from Latin obnoxiosus "hurtful, injurious," from obnoxius "subject, exposed to harm," from ob "to, toward" (see ob-) + noxa "injury, hurt, damage entailing liability" (from PIE root *nek- (1) "death"). Meaning "subject to something harmful, exposed to injury" is by 1590s. The main modern meaning "offensive, hateful, highly objectionable" is a shifted sense recorded from 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.
"to darken, cloud, overcloud," 1580s, from Latin obnibulatus, past participle of obnubilare "to cover with clouds or fog," from ob "in front of, against" (see ob-) + verb from Latin nubes "cloud," from PIE *sneudh- "fog" (see nuance). Related: Obnubilated; obnubilating. Middle English had obnubilous "obscure, indistinct" (early 15c.).
"act of making dark or obscure; fact of being overclouded," c. 1600, noun of action from obnubilate (v.).
also o.b.o., abbreviation of or best offer, by 1969 in for-sale classified ads.
"wooden, double-reeded wind instrument, 1724, from Italian oboe, from phonological spelling of 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. Also compare shawm. Related: Oboist (by 1830). "The tone is small, but highly individual and penetrating; it is especially useful for pastoral effects, for plaintive and wailing phrases, and for giving a reedy quality to concerted passages." [Century Dictionary]
ancient Greek small coin and weight, 1660s, from Latin obolus, from Greek obolos, the name of a coin (sixth part of a drachme); identical with obelos "a spit, needle, broach; bar of metal used as a coin or weight" (see obelisk). So called from the original shape. Middle English had obolus as the name of a small measure of weight, also ob "halfpenny," from Latin ob., abbreviation of obolus.
"the obtaining or trying to obtain something by craft or deception," 1610s, from Latin obreptionem (nominative obreptio) "a creeping or stealing on," noun of action from past-participle stem of obrepere "to creep on, creep up to," from ob "on, to" (see ob-) + repere "to creep" (see reptile). Opposed to subreption, which is to obtain something by suppression of the truth. Related: Obreptious.