buttoned-up vs colloquialism

buttoned-up is not a noun while colloquialism is a noun.

Word	Noun	Adjective	Verb	Adverb
buttoned-up	No	Yes	No	No
colloquialism	Yes	No	No	No

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

buttoned-up (adjective)	colloquialism (adjective)
conservative in professional manner
(British colloquial) not inclined to conversation