fiddle fist Share definition Flag When a person shoves their left fist up another persons ass and movies their right arm as if playing a song on a fiddle. Last night after the party, that guy came over to my house and fiddle fisted the shit out of me! fiddle fist by peter griffin, jr. June 6, 2009 0 0 Get merch Get the fiddle fist mug. Buy Now — $32.95 See more merch