fakeyoudaoicibaDictYouDict[fake 词源字典]
fake: [19] The use of fake for ‘produce a fraudulent copy of’ is a comparatively recent development. It used to mean ‘do up something spurious to make it seem genuine’, and in this sense seems to be a descendant of the longobsolete verb feague [16]. Essentially it is a piece of underworld slang, and as such has a rather slippery semantic history. In the 19th century it was used, like its ancestor feague, for any number of nefarious operations, including beating up and killing (‘to fake a man out and out, is to kill him’, J H Vaux, Vocabulary of the Flash Language 1812), but its current sense leads back in a straight line to its probable ultimate source, German fegen ‘polish, refurbish’.

This (like English fig ‘clothes, array’) was a derivative of the prehistoric Germanic base *feg-, a variant of *fag-, from which English gets fair ‘beautiful’.
=> fair, feast, fig[fake etymology, fake origin, 英语词源]
fakeyoudaoicibaDictYouDict
of unknown origin; attested in London criminal slang as adjective (1775 "a counterfeit"), verb (1812 "to rob"), and noun (1851, "a swindle;" of persons 1888, "a swindler"), but probably older. A likely source is feague "to spruce up by artificial means," from German fegen "polish, sweep," also "to clear out, plunder" in colloquial use. "Much of our early thieves' slang is Ger. or Du., and dates from the Thirty Years' War" [Weekley]. Or it may be from Latin facere "to do." Century Dictionary notes that "thieves' slang is shifting and has no history."

The nautical word meaning "one of the windings of a cable or hawser in a coil" probably is unrelated, from Swedish veck "a fold." As a verb, "to feign, simulate" from 1941. To fake it is from 1915, jazz slang; to fake (someone) out is from 1940s, originally in sports. Related: Faked; fakes; faking. The jazz musician's fake book is attested from 1951.