Online Etymology Dictionary

off-and-on (adv.): "intermittently," 1530s; see off (adv.) + on. As an adjective from 1580s.
off-base (adv.): "unawares," 1936, American English, from off (adv.) + base (n.); a figurative extension from baseball sense of "not in the right position" (1898), from notion of a baserunner being picked off while taking a lead.
off-beat (adj.): also offbeat, "unusual," 1938, from off (adv.) + beat (n.). From earlier sense in reference to from music rhythm (1927).
off-Broadway (adj.): 1953, "experimental theater productions in New York City," from off (adv.) + Broadway. Even more experimental off-off-Broadway is attested from 1967.
off-camera (adj.): 1944, from off (adv.) + camera.
off-chance (n.): 1861, from off (adv.) + chance (n.).
off-color (adj.): 1858, from off (adv.) + color (n.); originally used of gems; figurative extension to "of questionable taste, risqué" is American English, 1867.
off-colour (adj.): see off-color.
off-duty (adj.): 1743, from off (adv.) + duty.
off-hand (adv.): also offhand, 1690s, "at once, straightway," from off (adv.) + hand (n.). Probably originally in reference to shooting without a rest or support. Hence, of speech or action, "unpremeditated" (1719). Related: Off-handed; off-handedly.
off-key (adj.): 1920, from off (adv.) + musical sense of key (n.1). Figurative sense is from 1943.
off-limits (adj.): "forbidden," by 1881, U.S. military academies jargon, from off (adv.) + limit (n.). Earlier (1857) it was applied to cadets, etc., who were in violation of the limitations on their movement and behavior.
off-line (adj.): 1926, of railroads; 1950, of computers; from off (adv.) + line (n.).
off-load (v.): "unload," 1850, from off (adv.) + load (v.). Originally S.African, on model of Dutch afladen.
off-peak (adj.): 1906, originally in reference to electrical systems, from off (adv.) + peak (n.).
off-putting: 1570s, "procrastinating," from off (adv.) + put (v.). Meaning "creating an unfavorable impression" is first recorded 1894.
off-ramp (n.): 1954, from off (adv.) + ramp (n.).
off-road (adj.): 1949, from off (adv.) + road.
off-season (n.): 1848, "a period when business is down," from off (adv.) + season (n.).
off-shore (adj.): also off shore, 1720, from off + shore (n.). American English use for "other than the U.S." is from 1948 and the Marshall Plan.
off-site (adj.): 1956, from off (adv.) + site (n.).
off-stage (adj.): also offstage, 1915, from off (adv.) + stage (n.).
off-street (adj.): 1929, from off (adv.) + street.
off-white (n.): "white with a tinge of gray or yellow," 1927, from off (adv.) + white (n.).
offal (n.): late 14c., "waste parts, refuse," from off + fall (v.); the notion being that which "falls off" the butcher's block; perhaps a translation of Middle Dutch afval.
offence (n.): see offense.
offend (v.): early 14c., "to sin against (someone)," from Old French ofendre "transgress, antagonize," and directly from Latin offendere "to hit, strike against," figuratively "to stumble, commit a fault, displease, trespass against, provoke," from ob "against" (see ob-) + -fendere "to strike" (found only in compounds; see defend).

Meaning "to violate (a law), to make a moral false step, to commit a crime" is from late 14c. Meaning "to wound the feelings" is from late 14c. The literal sense of "to attack, assail" is attested from late 14c.; this has been lost in Modern English, but is preserved in offense and offensive. Related: Offended; offending.
offender (n.): mid-15c., agent noun from offend (v.). Earlier was offendour (early 15c.), from Anglo-French.
offense (n.): late 14c., "hurt, harm, injury, pain," from Old French ofense "offense, insult, wrong" (13c.) and directly from Latin offensa "an offense, injury, affront, crime," literally "a striking against," noun use of fem. past participle of offendere (see offend). Meaning "action of attacking" and "feeling of being hurt" are both first recorded c.1400. Sense of "breach of the law, transgression" is first recorded late 14c. Sporting sense first recorded 1894.
offensive (adj.): "attacking" (1540s), "insulting" (1570s), both from Middle French offensif (16c.) and directly from Medieval Latin offensivus, from Latin offens-, past participle stem of offendere "offend" (see offend). Related: Offensively; offensiveness.
offensive (n.): "condition of attacking, aggressive action," 1720, from offensive (adj.).
offer (v.): Old English ofrian "to offer, show, exhibit, sacrifice, bring an oblation," from Latin offerre "to present, bestow, bring before" (in Late Latin "to present in worship"), from ob "to" (see ob-) + ferre "to bring, to carry" (see infer). The Latin word was borrowed elsewhere in Germanic, e.g. Old Frisian offria, Middle Dutch offeren, Old Norse offra. Non-religious sense reinforced by Old French offrir "to offer," from Latin offerre. Related: Offered; offering.
offer (n.): early 15c., from Old French ofre "act of offering; offer, proposition" (12c.), verbal noun from offrir (see offer (v.)). The native noun formation is offering.
offering (n.): late Old English offrung "the presenting of something to a deity; a thing so presented," verbal noun from offrian (see offer (v.)). Of presentations to a person from mid-15c.; to the public from 1834.
offertory (n.): "the part of a Mass at which offerings are made," late 14c., from Medieval Latin offertorium "place where offerings are brought," from Vulgar Latin offertus, corresponding to Latin oblatus, past participle of offerre (see offer (v.)). Meaning "part of a religious service" is first recorded 1530s; sense of "collection of money" is from 1862.
office (n.): mid-13c., "a post, an employment to which certain duties are attached," from Anglo-French and Old French ofice "place or function; divine service" (12c. in Old French) or directly from Latin officium "service, kindness, favor; official duty, function, business; ceremonial observance," (in Ecclesiastical Latin, "church service"), literally "work-doing," from ops (genitive opis) "power, might, abundance, means" (related to opus "work;" see opus) + stem of facere "do, perform" (see factitious). Meaning "place for conducting business" first recorded 1560s. Office hours attested from 1841.
officer (n.): early 14c., "one who holds an office" (originally a high office), from Old French oficier "officer, official" (early 14c.), from Medieval Latin officarius "an officer," from Latin officium "a service, a duty" (see office). The military sense is first recorded 1560s. Applied to petty officials of justice from 16c.; U.S. use in reference to policemen is from 1880s.
official (n.): early 14c., from Old French oficial "law officer; bishop's representative" (12c.) and directly from Late Latin officialis "attendant to a magistrate, public official," noun use of officialis (adj.) "of or belonging to duty, service, or office" (see official (adj.)). Meaning "person in charge of some public work or duty" first recorded 1550s.
official (adj.): late 14c., "performing a service; required by duty," from Old French oficial "official; main, principal" (14c., Modern French officiel) or directly from Late Latin officialis "of or belonging to duty, service, or office," from Latin officium (see office). Meaning "pertaining to an office or official position" is from c.1600.
officialese (n.): "language of officialdom," 1881, from official + -ese.
officiant (n.): 1844, from noun use of Medieval Latin officiantem (nominative officians), present participle of officiare "perform religious services," from Latin officium (see office).
officiate (v.): 1630s, "to perform a duty," especially "to perform the duty of a priest," from Medieval Latin officiatum, from present participle of officiare "perform religious services," from Latin officium (see office). Related: Officiated; officiating.
officinal (adj.): "kept in stock by a druggist," c.1720, from French officinal, from Medieval Latin officinalis, literally "of or belonging in an officina," a storeroom (of a monastery) for medicines and necessaries, in classical Latin "workshop, manufactory, laboratory," contraction of *opificina, from opifex (genitive opificis) "worker, workman, maker, doer" (from opus "work;" see opus) + -fex, -ficis "one who does," from facere "do, perform" (see factitious). Related: Officinally.
officious (adj.): 1560s, "zealous, eager to serve," from Latin officiosus "full of courtesy, dutiful, obliging," from officium "duty, service" (see office). Sense of "meddlesome, doing more than is asked or required" had emerged by 1600 (in officiously). An officious lie (1570s) is one told to do good to another person (from Latin mendocium officiosum or French mensonge officieux). Related: Officiousness.
offing (n.): in phrase in the offing, 1779, from nautical term offing "the more distant part of the sea as seen from the shore" (1620s), from off (q.v.) + noun suffix -ing (1). Originally the phrase meant "in the distant future;" modern sense of "impending" developed 1914.
offset (n.): 1550s, "act of setting off" (on a journey, etc.), from off + set (adj.). Meaning "something 'set off' against something else, a counterbalance" is from 1769; the verb in this sense is from 1792. As a type of printing, in which the inked impression is first made on a rubber roller then transferred to paper, it is recorded from 1906.
offshoot (n.): 1670s, in figurative sense, of family trees; 1801 in general sense of "a derivative;" 1814 in literal sense, in reference to plants. From off + shoot (n.).
offshoring (n.): in the economic sense, as a form of outsourcing, attested by 1988, from offshore.
offside: also off-side, 1867, in various sporting senses, originally in English football; from off + side (n.).
offspring (n.): Old English ofspring "children or young collectively, descendants," literally "those who spring off (someone,)" from off + springan "to spring" (see spring (v.)). The figurative sense is first recorded c.1600.