Someone deranged and possibly dangerous
English: crazy, loony, looney, nutcase, weirdo
loonyEnglish
loony, around the bend, balmy, barmy, bats
Noun
Adjective
Informal or slang terms for mentally irregular
English: 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