possibly (adv.) Look up possibly at Dictionary.com
c. 1400, from possible (adj.) + -ly (2).
POSSLQ Look up POSSLQ at Dictionary.com
1979, acronym from person of opposite sex sharing living quarters; it never was an official category.
possum (n.) Look up possum at Dictionary.com
1610s, shortened form of opossum. Phrase play possum is first recorded 1822.
post (n.1) Look up post at Dictionary.com
"a timber set upright," from Old English post "pillar, doorpost," and Old French post "post, upright beam," both from Latin postis "door, post, doorpost," perhaps from por- "forth" (see pro-) + stare "to stand," from PIE root *stā- "to stand, set down, make or be firm" (see stet).

Similar compounds are Sanskrit prstham "back, roof, peak," Avestan parshti "back," Greek pastas "porch in front of a house, colonnade," Middle High German virst "ridepole," Lithuanian pirstas, Old Church Slavonic pristu "finger" (PIE *por-st-i-).
post (n.2) Look up post at Dictionary.com
"place when on duty," 1590s, from Middle French poste "place where one is stationed," also, "station for post horses" (16c.), from Italian posto "post, station," from Vulgar Latin *postum, from Latin positum, neuter past participle of ponere "to place, to put" (see position (n.)). Earliest sense in English was military; meaning "job, position" is attested 1690s.
post (n.3) Look up post at Dictionary.com
"mail system," c. 1500, "riders and horses posted at intervals," from post (n.2) on notion of riders and horses "posted" at intervals along a route to speed mail in relays, probably formed on model of Middle French poste in this sense (late 15c.). Meaning "system for carrying mail" is from 1660s.
post (v.4) Look up post at Dictionary.com
"to put up bail money," 1781, from one of the nouns post, but which one is uncertain. Related: Posted; posting.
post (v.1) Look up post at Dictionary.com
"to affix (a paper, etc.) to a post" (in a public place), hence, "to make known," 1630s, from post (n.1). Related: Posted; posting.
post (v.2) Look up post at Dictionary.com
in bookkeeping, "to transfer from a day book to a formal account," 1620s, from post (n.2) via a figurative sense of "carrying" by post horses. Related: Posted; posting.
post (v.3) Look up post at Dictionary.com
"to send through the postal system," 1837, from post (n.3). Earlier, "to travel with relays of horses" (1530s). Related: Posted; posting.
post (v.5) Look up post at Dictionary.com
"to station at a post," from post (n.2). Related: Posted; posting.
post (adv.) Look up post at Dictionary.com
1540s, "with post horses," hence, "rapidly;" especially in the phrase to ride post "go rapidly," from post (n.3).
post factum Look up post factum at Dictionary.com
Latin, literally "after the fact," from factum "deed, act" (see fact).
post hoc Look up post hoc at Dictionary.com
Latin, "after this." Especially in post hoc, ergo propter hoc, logical fallacy, literally "after this, therefore because of this."
post meridiem Look up post meridiem at Dictionary.com
"after noon," 1640s, Latin, from post "after" (see post-) + accusative of meridies (see meridian).
post office (n.) Look up post office at Dictionary.com
1650s, "public department in charge of letter-carrying," from post (n.3) + office. Meaning "building where postal business is carried on" is from 1650s. In slang or euphemistic sense of "a sexual game" it refers to an actual parlor game first attested early 1850s in which pretend "letters" were paid for by kisses.
post restante Look up post restante at Dictionary.com
direction on mail that it be held at that post office until called for, French, literally "remaining post."
post- Look up post- at Dictionary.com
word-forming element meaning "after," from Latin post "behind, after, afterward," from *pos-ti (source also of Arcadian pos, Doric poti "toward, to, near, close by;" Old Church Slavonic po "behind, after," pozdu "late;" Lithuanian pas "at, by"), from PIE *apo- (source also of Greek apo "from," Latin ab "away from" see apo-).
post-bellum (adj.) Look up post-bellum at Dictionary.com
also postbellum, used in U.S. South from 1874 in reference to American Civil War; see post- + bellicose.
post-classical (adj.) Look up post-classical at Dictionary.com
1845, from post- + classical.
post-glacial (adj.) Look up post-glacial at Dictionary.com
1855, from post- + glacial.
post-graduate (adj.) Look up post-graduate at Dictionary.com
also postgraduate, 1858, originally American English, from post- + graduate (adj.). As a noun, attested from 1890. Abbreviation post-grad is recorded from 1950.
post-hole (n.) Look up post-hole at Dictionary.com
1703, from post (n.1) + hole (n.).
post-impressionism (n.) Look up post-impressionism at Dictionary.com
1910, from post- + impressionism.
Post-it (n.) Look up Post-it at Dictionary.com
1975, proprietary name.
post-millennial (adj.) Look up post-millennial at Dictionary.com
also postmillennial, 1831, from post- "after" + millennial; chiefly in reference to the Protestant doctrine that the second coming of Christ will occur after, not at, the Christian millennium.
post-modern (adj.) Look up post-modern at Dictionary.com
also post-modern, post modern, by 1919, in frequent use from 1949, from post- + modern.
But it has been only during the later decades of the modern era -- during that time interval that might fairly be called the post-modern era -- that this mechanistic conception of things has begun seriously to affect the current system of knowledge and belief; and it has not hitherto seriously taken effect except in technology and in the material sciences. [Thorstein Veblen, "The Vested Interests and the Common Man," 1919]

So much for the misapplied theory which has helped set the artist's nerves a-quiver and incited him to the extremes of post modern art, literary and other. [Wilson Follett, "Literature and Bad Nerves," "Harper's," June 1921]
Of architecture from 1940s; specific sense in the arts emerged 1960s (see postmodernism).
post-mortem (adj.) Look up post-mortem at Dictionary.com
also postmortem, 1734 (adverb), from Latin post mortem, from post "after" (see post-) + mortem, accusative of mors "death" (see mortal (adj.)). From 1835 as an adjective. As a noun, shortening of post-mortem examination, it is recorded from 1850.
post-operative (adj.) Look up post-operative at Dictionary.com
also postoperative, "occurring after a surgical operation," 1869, from post- + operative. Short form post-op is attested from 1971.
post-partum (adj.) Look up post-partum at Dictionary.com
also postpartum, 1837, "occurring after birth," from Latin post partum "after birth," from post "after" (see post-) + accusative of partus "a bearing, a bringing forth," from partus, past participle of parere "to bring forth" (see pare). Phrase Post-partum depression first attested 1929.
postage (n.) Look up postage at Dictionary.com
1580s, "sending of mail by post;" 1650s as "cost of sending something by mail," from post (n.3) + -age. Postage stamp is attested from 1840; they were recorded as being collected in albums by 1862.
postal (adj.) Look up postal at Dictionary.com
"pertaining to the mail system," 1843, on model of French postale (1836), from post (n.3). Noun meaning "state of irrational and violent anger" (usually in phrase going postal) attested by 1997, in reference to a cluster of news-making workplace shootings in U.S. by what were commonly described as "disgruntled postal workers" (the cliche itself, though not the phrase, goes back at least to 1994).
postcard (n.) Look up postcard at Dictionary.com
1870, from post (n.3) + card (n).
postdate (v.) Look up postdate at Dictionary.com
also post-date, 1620s, from post- + date (v.1) "to assign a date to, to mark a date on." Related: Postdated; postdating. Intransitive meaning "be of an earlier date" is from 1909.
postdiluvial (adj.) Look up postdiluvial at Dictionary.com
also post-diluvial, 1823, from post- + diluvial. Earlier was postdiluvian (1670s).
posted (adj.) Look up posted at Dictionary.com
"supplied with news," 1828, American English, past participle adjective from post (v.2).
poster (n.) Look up poster at Dictionary.com
"bill, placard, thing posted," 1838, from post (v.1). Poster boy/girl/child "someone given prominence in certain causes" is attested by 1990, in reference to fund-raising drives for charities associated with disability, featuring child sufferers, a feature since 1930s.
posterior (adj.) Look up posterior at Dictionary.com
1530s, "later," from Latin posterior "after, later, behind," comparative of posterus "coming after, subsequent," from post "after" (see post-). Meaning "situated behind" is from 1630s.
posterior (n.) Look up posterior at Dictionary.com
"buttocks," euphemistic, 1610s, from posterior (adj.). Earlier it meant "those who come after, posterity" (1530s). Compare Lithuanian pasturas "the last, the hindmost," from pas "at, by."
posteriority (n.) Look up posteriority at Dictionary.com
late 14c., "state of being behind," from Old French posteriorite (Modern French postériorité), from Medieval Latin posterioritatem (nominative posterioritas), from Latin posterior "later" (see posterior (adj.)).
posterity (n.) Look up posterity at Dictionary.com
late 14c., from Old French posterité (14c.), from Latin posteritatem (nominative posteritas) "future, future time; after-generation, offspring;" literally "the condition of coming after," from posterus "coming after, subsequent," from post "after" (see post-). Old English words for this included æftercneoreso, framcynn.
postern (n.) Look up postern at Dictionary.com
late 13c., "back door, private door," from Old French posterne "side or rear gate," earlier posterle, from Late Latin posterula "small back door or gate," diminutive of Latin posterus "that is behind, coming after, subsequent," from post "after" (see post-).
posthaste (adv.) Look up posthaste at Dictionary.com
1590s, from a noun (1530s) meaning "great speed," usually said to be from "post haste" instruction formerly written on letters (attested from 1530s), from post (adv.) + haste (n.). The verb post "to ride or travel with great speed" is recorded from 1550s.
posthumous (adj.) Look up posthumous at Dictionary.com
mid-15c., "born after the death of the originator" (author or father), from Late Latin posthumus, from Latin postumus "last, last-born," superlative of posterus "coming after, subsequent" (see posterior). Altered in Late Latin by association with Latin humare "to bury," suggesting death; the one born after the father's death obviously being the last. An Old English word for this was æfterboren, literally "after-born." Related: Posthumously.
postillon (n.) Look up postillon at Dictionary.com
1590s, from Middle French postillon (1530s), from Italian postiglione "forerunner, guide," especially for one carrying mail on horseback, from posta "mail" (see post (n.3)) + compound suffix from Latin -ilio.
postlude (n.) Look up postlude at Dictionary.com
1821, from post- + ending abstracted from prelude.
postman (n.) Look up postman at Dictionary.com
1520s, from post (n.3) + man (n.).
postmark (n.) Look up postmark at Dictionary.com
1670s, from post (n.3) + mark (n.1). As a verb from 1716. Related: Postmarked; postmarking.
postmaster (n.) Look up postmaster at Dictionary.com
1510s, from post (n.3) + master (n.).
postmodernism (n.) Look up postmodernism at Dictionary.com
also post-modernism, by 1977, from post- + modernism. Defined by Terry Eagleton as "the contemporary movement of thought which rejects ... the possibility of objective knowledge" and is therefore "skeptical of truth, unity, and progress" ["After Theory," 2003]. Related: post-modernist (1965).