colloquialism vs dotty

colloquialism is a noun but dotty is not a noun.

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

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

colloquialism (adjective)	dotty (adjective)
	intensely enthusiastic about or preoccupied with
	informal or slang terms for mentally irregular