hardball vs baseball

hardball and baseball both are nouns.

Word	Noun	Adjective	Verb	Adverb
hardball	Yes	No	No	No
baseball	Yes	No	No	No

As nouns, baseball is a hypernym of hardball; that is, baseball is a word with a broader meaning than hardball:

hardball: baseball as distinguished from softball
baseball: a ball game played with a bat and ball between two teams of nine players; teams take turns at bat trying to score runs

Other hypernyms of hardball include ball, baseball game.

hardball (noun)	baseball (noun)
baseball as distinguished from softball	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 no-nonsense attitude in business or politics	a ball used in playing baseball