baseball vs pop-up

baseball and pop-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
baseball	Yes	No	No	No
pop-up	Yes	No	No	No

baseball (noun)	pop-up (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 short high fly ball
a ball used in playing baseball	a store that is open for a limited period of time on temporary premises
	a book (usually for children) that contains one or more pages such that a three-dimensional structure rises up when a page is opened