gloomy Gus vs colloquialism

gloomy Gus and colloquialism both are nouns.

Word	Noun	Adjective	Verb	Adverb
gloomy Gus	Yes	No	No	No
colloquialism	Yes	No	No	No

gloomy Gus (noun)	colloquialism (noun)
someone with a habitually sullen or gloomy expression	a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech