1894, in the meaning defined at sense 1circa 1925, in the meaning defined above

of uncertain origin

NOTE: The word fink is apparently first attested in a sketch by the American humorist George Ade, "'Stumpy' and Other Interesting People," first printed in the Chicago Record on March 17, 1894. It has traditionally been compared with German Fink, literally, "finch" (see finch), used in various pejorative compounds, as Dreckfink (Dreck "filth"), Mistfink (Mist "manure"), Schmierfink (Schmiere "grease"), referring to a dirty or untidy person (Mistfink, at least, is known from the end of the 15th century); or with Fink in German university slang referring to someone who did not belong to a student association (Burschenschaft). Probably of more relevance to the English word is the recording of Fink, Finke in German criminal argot (Rotwelsch) as one of many variants (also Pink, Pincke, Pünke, Bink, Bing, Fünke) with the meaning "contemptible person" (recorded by the criminologist Friedrich Avé-Lallemant in his "Wörterbuch der Gaunersprache," in vol. 4 of Das Deutsche Gaunerthum, Leipzig, 1862). These forms are clearly dependent on a Dutch, Frisian and Low German etymon meaning "little finger" (see pinkie entry 2), extended to mean "penis" (a sense recorded for East Frisian pink, and a meaning of both Fink and Pink in Low German according to Avé-Lallemant) and then "contemptible person."

derivative of fink entry 1