from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Slang Eccentric or irrational: a wacky person.
- adj. Slang Crazy; silly: a wacky outfit.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of a person or their behaviour, zany.
- n. Alternative form of wacke.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. informal or slang terms for mentally irregular
- adj. ludicrous, foolish
Variant of whacky, probably from the phrase out of whack; see whack.(American Heritage® Dictionary of the English Language, Fourth Edition)