security blanket vs colloquialism

security blanket and colloquialism both are nouns.

Word	Noun	Adjective	Verb	Adverb
security blanket	Yes	No	No	No
colloquialism	Yes	No	No	No

security blanket (noun)	colloquialism (noun)
a blanket (or toy) that a child carries around in order to reduce anxiety	a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech
anything that an adult person uses to reduce anxiety