NUT

(HEAD) [noun] [C] [informal] - a person's heada bang on the nutCome on, use your nut (= think clearly)! You do it like this.(UK and ANZ) If you do your nut, you become extremely angry.My Mum'll do her nut when she finds out I failed all my exams.Someone who is off their nut is behaving in a foolish or stupid way.You can't do that! Are you off your nut?