number one vs colloquialism

number one and colloquialism both are nouns.

Word	Noun	Adjective	Verb	Adverb
number one	Yes	No	No	No
colloquialism	Yes	No	No	No

number one (noun)	colloquialism (noun)
a reference to yourself or myself etc.; `take care of number one' means to put your own interests first	a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech
the first element in a countable series
the first or highest in an ordering or series