Similar Words to Whacky:
Around The Bend
Balmy
Barmy
Bats
Batty
Bonkers
Buggy
Cockamamie
Cockamamy
Cracked
Crackers
Daft
Dotty
Fruity
Goofy
Haywire
Kookie
Kooky
Loco
Loony
Loopy
Nuts
Nutty
Round The Bend
Sappy
Silly
Wacky
Zany
Definitions of Whacky:
1. Ludicrous, foolish
2. Informal or slang terms for mentally irregular