baseball game vs backstop

baseball game and backstop both are nouns.

Word	Noun	Adjective	Verb	Adverb
baseball game	Yes	No	No	No
backstop	Yes	No	Yes	No

baseball game (noun)	backstop (noun)
a ball game played with a bat and ball between two teams of nine players; teams take turns at bat trying to score runs	a precaution in case of an emergency
	(baseball) a fence or screen (as behind home plate) to prevent the ball from traveling out of the playing field
	(baseball) the person who plays the position of catcher

baseball game (verb)	backstop (verb)
	act as a backstop