colloquialism vs whacky

colloquialism is a noun but whacky is not a noun.

Word	Noun	Adjective	Verb	Adverb
colloquialism	Yes	No	No	No
whacky	No	Yes	No	No

colloquialism (noun)	whacky (noun)
a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech

colloquialism (adjective)	whacky (adjective)
	ludicrous, foolish
	informal or slang terms for mentally irregular