(as) mad as a meat axe

Primarily heard in Australia.

1. Enraged; extremely or inconsolably angry. My dad was mad as a meat axe after I crashed his car. You make me as mad as a meat axe with the way you carry on sometimes, you know that? Tiffany will be mad as a meat axe when she finds out that her so-called friends started that awful rumor about her.

2. Insane or eccentric. Don't leave me alone with Uncle Stu—he's mad as a meat axe! Who know what he'll do or say! I know some of my students think I'm as mad as a meat axe because of my weird methods. You're as mad as a meat axe if you believe this ridiculous scheme will work.