adjective, klutz·i·er, klutz·i·est. Slang. clumsy; awkward: If you weren't so klutzy you wouldn't have dropped it. unwieldy; bulky or awkward: a klutzy pair of boots. inept or thoughtless; boneheaded: a klutzy remark. adj.1965, from klutz + -y (2). Related: Klutziness.