Fail
Middle English: from Old French faillir (verb), faille (noun), based on Latin fallere ‘deceive’.
wiktionary
From Middle English failen, borrowed from Anglo-Norman faillir, from Vulgar Latin *fallire, alteration of Latin fallere(“to deceive, disappoint”), from Proto-Indo-European *bʰāl-(“to lie, deceive”) or Proto-Indo-European *sgʷʰh₂el-(“to stumble”). Compare Dutch feilen, falen(“to fail, miss”), German fehlen(“to fail, miss, lack”), Danish fejle(“to fail, err”), Swedish fela(“to fail, be wanting, do wrong”), Icelandic feila(“to fail”), Spanish fallar(“to fail, miss”).
Unknown. Compare Scottish Gaelic fàl(“hedge”), Scots faill(“turf”). Attested from the 16th century. [1]
etymonline
fail (v.)
c. 1200, "be unsuccessful in accomplishing a purpose;" also "cease to exist or to function, come to an end;" early 13c. as "fail in expectation or performance," from Old French falir "be lacking, miss, not succeed; run out, come to an end; err, make a mistake; be dying; let down, disappoint" (11c., Modern French faillir), from Vulgar Latin *fallire, from Latin fallere "to trip, cause to fall;" figuratively "to deceive, trick, dupe, cheat, elude; fail, be lacking or defective." De Vaan traces this to a PIE root meaning "to stumble" (source also of Sanskrit skhalate "to stumble, fail;" Middle Persian škarwidan "to stumble, stagger;" Greek sphallein "to bring or throw down," sphallomai "to fall;" Armenian sxalem "to stumble, fail"). If so, the Latin sense is a metaphorical shift from "stumble" to "deceive." Related: Failed; failing.
Replaced Old English abreoðan. From c. 1200 as "be unsuccessful in accomplishing a purpose;" also "cease to exist or to function, come to an end;" early 13c. as "fail in expectation or performance."
From mid-13c. of food, goods, etc., "to run short in supply, be used up;" from c. 1300 of crops, seeds, land. From c. 1300 of strength, spirits, courage, etc., "suffer loss of vigor; grow feeble;" from mid-14c. of persons. From late 14c. of material objects, "break down, go to pieces."
fail (n.)
late 13c., "failure, deficiency" (as in without fail), from Old French faile "deficiency," from falir (see fail (v.)). The Anglo-French form of the verb, failer, also came to be used as a noun, hence failure.
