colloquialism vs fiddling

colloquialism is a noun but fiddling is not a noun.

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

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

colloquialism (adjective)	fiddling (adjective)
	(informal) small and of little importance