word-forming element meaning "before," from Old French pre- and Medieval Latin pre-, both from Latin prae (adverb and preposition) "before in time or place," from PIE *peri- (source also of Oscan prai, Umbrian pre, Sanskrit pare "thereupon," Greek parai "at," Gaulish are- "at, before," Lithuanian prie "at," Old Church Slavonic pri "at," Gothic faura, Old English fore "before"), extended form of root *per- (1) "forward," hence "beyond, in front of, before."
The Latin word was active in forming verbs. Also see prae-. Sometimes in Middle English muddled with words in pro- or per-.
"act of flying," Old English flyht "a flying, act or power of flying," from Proto-Germanic *flukhtiz (source also of Dutch vlucht "flight of birds," Old Norse flugr, Old High German flug, German Flug "flight"), from Proto-Germanic *flugti-, suffixed form of PIE root *pleu- "to flow."
Spelling altered late 14c. from Middle English fliht (see fight (v.)). Sense of "swift motion" is from mid-13c.. Meaning "an instance of flight" is 1785, originally of ballooning. Sense of "a number of things passing through the air together" is from mid-13c. Meaning "series of stairs between landings" is from 1703. Figuratively, "an excursion" of fancy, imagination, etc., from 1660s. Flight-path is from 1908; flight-test (v.) from 1919; flight-simulator from 1947 (originally in rocketry); flight-attendant from 1946.