colloquialism vs straight up

colloquialism is a noun but straight up is not a noun.

Word	Noun	Adjective	Verb	Adverb
colloquialism	Yes	No	No	No
straight up	No	Yes	No	No

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

colloquialism (adjective)	straight up (adjective)
	(of an alcoholic drink) stirred or shaken with ice, but served without it