An Etymological Dictionary of the German Language/farzen

by Friedrich Kluge

farzen, vb., ‘to fart,’ from the equiv. MidHG. varzen (also vurzen, vërzen), allied to OHG. fërzan, ‘to fart’; corresponds to AS. feortan, E. to fart; OIc. (with transposition of the r), freta. Teut. root fert, from the Aryan perd, with the same meaning; comp. Sans. root pard, Gr. πέρδειν, Lith. pérdżu, pérsti, Russ. perdětĭ.