Etymology
Advertisement
flee (v.)

Old English fleon, flion "take flight, fly from, avoid, escape" (contracted class II strong verb; past tense fleah, past participle flogen), from Proto-Germanic *fleuhanan "to run away" (source also of Old High German fliohan, Old Norse flöja, Old Frisian flia, Dutch vlieden, German fliehen, Gothic þliuhan "to flee"), probably from PIE *pleuk-, extended form of root *pleu- "to flow," but Boutkan is not convinced. Also compare fly (v.2).

Weak past tense and past participle fled emerged in Middle English under influence of Scandinavian. Old English had a transitive form, geflieman "put to flight, banish, drive away," which came in handy in the Anglo-Saxon Chronicle. Related: fled; Fleeing.

Related entries & more 
Advertisement
fleer (n.)
"one who flees," late 14c., agent noun from flee (v.).
Related entries & more 
fled 
past tense and past participle of flee (q.v.) and fly (v.2).
Related entries & more 
fly (v.2)
"run away," Old English fleon, flion "fly from, avoid, escape;" essentially a variant spelling of flee (q.v.). In Old English, this verb and fleogan "soar through the air with wings" (modern fly (v.1)) differed only in their present tense forms and often were confused, then as now. In some Middle English dialects they seem to have merged completely. Distinguished from one another since 14c. in the past tense: flew for fly (v.1), fled for fly (v.2).
Related entries & more 
*pleu- 
Proto-Indo-European root meaning "to flow."

It forms all or part of: fletcher; fledge; flee; fleet (adj.) "swift;" fleet (n.2) "group of ships under one command;" fleet (v.) "to float, drift; flow, run;" fleeting; flight (n.1) "act of flying;" flight (n.2) "act of fleeing;" flit; float; flood; flotsam; flotilla; flow; flue; flugelhorn; fluster; flutter; fly (v.1) "move through the air with wings;" fly (n.) "winged insect;" fowl; plover; Pluto; plutocracy; pluvial; pneumo-; pneumonia; pneumonic; pulmonary.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit plavate "navigates, swims;" Greek plynein "to wash," plein "to navigate," ploein "to float, swim," plotos "floating, navigable," pyelos "trough, basin;" Latin plovere "to rain," pluvius "rainy;" Armenian luanam "I wash;" Old English flowan "to flow;" Old Church Slavonic plovo "to flow, navigate;" Lithuanian pilu, pilti "to pour out," plauju, plauti "to swim, rinse."
Related entries & more 
Advertisement
fugacious (adj.)
"fleeing, likely to flee," 1630s, with -ous + Latin fugaci-, stem of fugax "apt to flee, timid, shy," figuratively "transitory, fleeting," from fugere "to flee" (see fugitive). Related: Fugaciously; fugaciousness; fugacity.
Related entries & more 
subterfuge (n.)

1570s, from French subterfuge (14c.) or directly from Medieval Latin subterfugium "an evasion," from Latin subterfugere "to evade, escape, flee by stealth," from subter "beneath, below;" in compounds "secretly" (from PIE *sup-ter-, suffixed (comparative) form of *(s)up-; see sub-) + fugere "flee" (see fugitive (adj.)).

Related entries & more 
febrifuge (n.)
"medicine that reduces fever," 1680s, from French fébrifuge, literally "driving fever away," from Latin febris (see fever) + fugare "cause to flee, put to flight, drive off, chase away, rout," also used in reference to banishment and exile, derived verb from fuga "flight," from PIE *bhug-a-, suffixed form of root *bheug- (1) "to flee" (see fugitive (adj.)).
Related entries & more 
lucifugous (adj.)
"shunning light" (in reference to bats, cockroaches, etc.), 1650s, from Latin lucifugus "light-shunning," from stem of lucere "to shine" (from suffixed (iterative) form of PIE root *leuk- "light, brightness") + stem of fugax "apt to flee, timid," figuratively "transitory, fleeting," from fugere "to flee" (see fugitive (adj.)).
Related entries & more 
fugitive (adj.)

late 14c., "fleeing, having fled, having taken flight," from Old French fugitif, fuitif "absent, missing," from Latin fugitivus "fleeing," past-participle adjective from stem of fugere "to flee, fly, take flight, run away; become a fugitive, leave the country, go into exile; pass quickly; vanish, disappear, perish; avoid, shun; escape the notice of, be unknown to," from PIE root *bheug- "to flee" (source also of Greek pheugein "to flee, escape, go into exile, be on the run," phyza "(wild) flight, panic," phyge "flight, exile;" Lithuanian būgstu, būgti "be frightened," bauginti "frighten someone," baugus "timid, nervous;" perhaps also Avestan būj(i)- "penance, atonement," būjat "frees"). Old English had flyma.

Meaning "lasting but a short time, fleeting" is from c. 1500. Hence its use in literature for short compositions written for passing occasions or purposes (1766).

Related entries & more