balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loony, loopy, nuts, nutty, round the bend, around the bend, wacky, whacky(adj)

informal or slang terms for mentally irregular

"it used to drive my husband balmy"

bats(Adjective)

Mad, insane.

You must be bats to go out in the cold without a coat on.