Similar Words to Loony:
Around The Bend
Balmy
Barmy
Bats
Batty
Bonkers
Buggy
Cracked
Crackers
Crazy
Daft
Dotty
Fruity
Haywire
Kookie
Kooky
Loco
Looney
Loopy
Nutcase
Nuts
Nutty
Round The Bend
Wacky
Weirdo
Whacky
Definitions of Loony:
1. Someone deranged and possibly dangerous
2. Informal or slang terms for mentally irregular