colloquialism vs killjoy

colloquialism and killjoy both are nouns.

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

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