party pooper vs colloquialism

party pooper and colloquialism both are nouns.

Word	Noun	Adjective	Verb	Adverb
party pooper	Yes	No	No	No
colloquialism	Yes	No	No	No

party pooper (noun)	colloquialism (noun)
someone who spoils the pleasure of others	a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech