baseball team vs first base

baseball team and first base both are nouns.

Word	Noun	Adjective	Verb	Adverb
baseball team	Yes	No	No	No
first base	Yes	No	No	No

baseball team (noun)	first base (noun)
a team that plays baseball	the initial stage in accomplishing something
	the fielding position of the player on a baseball team who is stationed at first of the bases in the infield (counting counterclockwise from home plate)
	the base that must be touched first by a base runner in baseball