colloquialism vs chummy

colloquialism is a noun but chummy is not a noun.

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

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

colloquialism (adjective)	chummy (adjective)
	(used informally) associated on close terms
	(used colloquially) having the relationship of friends or pals