An Etymological Dictionary of the German Language/Annotated/farzen

by Friedrich Kluge

farzen, verb, ‘to fart,’ from the equivalent Middle High German varzen (also vurzen, vërzen), allied to Old High German fërzan, ‘to fart’; corresponds to Anglo-Saxon feortan, English to fart; Old Icelandic (with transposition of the r), freta. Teutonic root fert, from the Aryan perd, with the same meaning; compare Sanscrit root pard, Greek πέρδειν, Lithuanian pérdżu, pérsti, Russian perdětĭ.