Fustarcking Share definition Flag Defined as the censored version of the word Fuck. Used in cases where the speaker is not allowed to use cuss words. Person 1: Ow! Person 2: What? Person 1: I just got a Fustarcking paper cut! Person 2: Oh. Fustarcking by Unanimous Author February 25, 2011 Get the Fustarcking mug.