wacky

[ wak-ee ]
/ ˈwæk i /

adjective, wack·i·er, wack·i·est. Slang.

odd or irrational; crazy: They had some wacky plan for selling more books.
Also whacky.

Origin of wacky

1935–40; apparently whack (noun, as in out of whack) + -y1

Related forms

wack·i·ly, adverbwack·i·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for wackiness

wacky

/ (ˈwækɪ) /

adjective wackier or wackiest

slang eccentric, erratic, or unpredictable

Derived Forms

wackily, adverbwackiness, noun

Word Origin for wacky

C19 (in dialect sense: a fool, an eccentric): from whack (hence, a whacky, a person who behaves as if he had been whacked on the head)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012