goof / goōf/ inf. • n. 1. a mistake: he made one of the most embarrassing goofs of his tenure. 2. a foolish or stupid person. • v. [intr.] 1. spend time idly or foolishly; fool around: I was goofing around and broke my arm. ∎ (goof off) evade a duty; idle or shirk: he was goofing off from his math homework. ∎ (goof on) make fun of; ridicule: Lew and I started goofing on Alison's friend. 2. make a mistake; blunder: you're scared to say yes in case you goof up.