"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.
1590s, "one who intends;" 1620s as "one who puts forth a claim;" agent noun from pretend (v.). Specifically of a claimant to the English throne from 1690s, especially the Old and Young Pretenders, the son and grandson of James II who asserted claims to the throne against the Hanoverians. Meaning "one who feigns, one who makes a false show, one who puts forth a claim without adequate grounds" is from 1630s.
Having been a spectator of the battle of the Boyne, on the first of July 1690, he thought it most prudent, while the fate of the day was yet undecided, to seek for safety in flight. In a few hours he reached the castle of Dublin, where he was met by Lady Tyrconnel, a woman of spirit. "Your countrymen (the Irish), Madam," said James, as he was ascending the stairs, "can run well."—"Not quite so well as your Majesty," retorted her Ladyship ; "for I see you have won the race." [anecdote of the Old Pretender, first, as far as I can tell, in Charles Wilson's "Polyanthea," 1804]