word-forming element meaning "forward, forth, toward the front" (as in proclaim, proceed); "beforehand, in advance" (prohibit, provide); "taking care of" (procure); "in place of, on behalf of" (proconsul, pronoun); from Latin pro (adv., prep.) "on behalf of, in place of, before, for, in exchange for, just as," which also was used as a first element in compounds and had a collateral form por-.

Also in some cases from cognate Greek pro "before, in front of, sooner," which also was used in Greek as a prefix (as in problem). Both the Latin and Greek words are from PIE *pro- (source also of Sanskrit pra- "before, forward, forth;" Gothic faura "before," Old English fore "before, for, on account of," fram "forward, from;" Old Irish roar "enough"), extended form of root *per- (1) "forward," hence "in front of, before, toward, near," etc.

The common modern sense of "in favor of, favoring" (pro-independence, pro-fluoridation, pro-Soviet, etc.) was not in classical Latin and is attested in English from early 19c.

*stā-, Proto-Indo-European root meaning "to stand, set down, make or be firm," with derivatives meaning "place or thing that is standing."

It forms all or part of: Afghanistan; Anastasia; apostasy; apostate; armistice; arrest; assist; astatic; astatine; Baluchistan; bedstead; circumstance; consist; constable; constant; constitute; contrast; cost; desist; destination; destine; destitute; diastase; distance; distant; ecstasy; epistasis; epistemology; establish; estaminet; estate; etagere; existence; extant; Hindustan; histidine; histo-; histogram; histology; histone; hypostasis; insist; instant; instauration; institute; interstice; isostasy; isostatic; Kazakhstan; metastasis; obstacle; obstetric; obstinate; oust; Pakistan; peristyle; persist; post (n.1) "timber set upright;" press (v.2) "force into service;" presto; prostate; prostitute; resist; rest (v.2) "to be left, remain;" restitution; restive; restore; shtetl; solstice; stable (adj.) "secure against falling;" stable (n.) "building for domestic animals;" stage; stalag; stalwart; stamen; -stan; stance; stanchion; stand; standard; stanza; stapes; starboard; stare decisis; stasis; -stat; stat; state (n.1) "circumstances, conditions;" stater; static; station; statistics; stator; statue; stature; status; statute; staunch; (adj.) "strong, substantial;" stay (v.1) "come to a halt, remain in place;" stay (n.2) "strong rope which supports a ship's mast;" stead; steed; steer (n.) "male beef cattle;" steer (v.) "guide the course of a vehicle;" stem (n.) "trunk of a plant;" stern (n.) "hind part of a ship;" stet; stoa; stoic; stool; store; stound; stow; stud (n.1) "nailhead, knob;" stud (n.2) "horse kept for breeding;" stylite; subsist; substance; substitute; substitution; superstition; system; Taurus; understand.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tisthati "stands;" Avestan histaiti "to stand;" Persian -stan "country," literally "where one stands;" Greek histēmi "put, place, cause to stand; weigh," stasis "a standing still," statos "placed," stylos "pillar;" Latin sistere "stand still, stop, make stand, place, produce in court," status "manner, position, condition, attitude," stare "to stand," statio "station, post;" Lithuanian stojuos "I place myself," statau "I place;" Old Church Slavonic staja "place myself," stanu "position;" Gothic standan, Old English standan "to stand," stede "place;" Old Norse steði "anvil;" Old Irish sessam "the act of standing."

"supplied with news or full information," 1828, American English, past-participle adjective from post (v.2).

late 14c., posicioun, as a term in logic and philosophy, "statement of belief, the laying down of a proposition or thesis," from Old French posicion "position, supposition" (Modern French position) and directly from Latin positionem (nominative positio) "act or fact of placing, situation, position, affirmation," noun of state from past-participle stem of ponere "put, place." Watkins tentatively identifies this as from PIE *po-s(i)nere, from *apo- "off, away" (see apo-) + *sinere "to leave, let" (see site). But de Vaan identifies it as from Proto-Italic *posine-, from PIE *tkine- "to build, live," from root *tkei- "to settle, dwell, be home" (see home (n.)).

The meaning "place occupied by a person or thing" especially a proper or appropriate place, is from 1540s; hence "status, standing, social rank" (1832); "official station, employment" (1890). The meaning "manner in which some physical thing is arranged or posed, aggregate of the spatial relations of a body or figure to other such bodies or figures" is recorded by 1703; specifically in reference to dance steps, 1778, to sexual intercourse, 1883. Military sense of "place occupied or to be occupied" is by 1781.

also bed-post, "post forming an angle of a bed frame," 1590s, from bed (n.) + post (n.1). Formerly they were made high to support a canopy and rods for a curtain.

bedstead with high corner posts, 1836, from four + post (n.).

1834, from goal (n.) + post (n.1). To move the goal posts as a figurative expression for "cheat by changing the objectives after the process has begun" is by 1988.

also guidepost, 1761, from guide (v.) + post (n.1). Placed at a fork or intersection, with signs to guide travelers on their way.

also lamppost, 1731, from lamp + post (n.1).

also mile-post, "post set up to mark the distance by miles along a highway, etc.," 1768, from mile + post (n.1).