honest-to-god vs colloquialism

honest-to-god is not a noun while colloquialism is a noun.

Word	Noun	Adjective	Verb	Adverb
honest-to-god	No	Yes	No	No
colloquialism	Yes	No	No	No

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

honest-to-god (adjective)	colloquialism (adjective)
(used informally especially for emphasis) real or genuine