colloquialism vs dead ringer

colloquialism and dead ringer both are nouns.

Word	Noun	Adjective	Verb	Adverb
colloquialism	Yes	No	No	No
dead ringer	Yes	No	No	No

colloquialism (noun)	dead ringer (noun)
a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech	a person who is almost identical to another