twirler vs ballplayer

twirler and ballplayer both are nouns.

Word	Noun	Adjective	Verb	Adverb
twirler	Yes	No	No	No
ballplayer	Yes	No	No	No

As nouns, ballplayer is a hypernym of twirler; that is, ballplayer is a word with a broader meaning than twirler:

Other hypernyms of twirler include baseball player, thrower.

twirler (noun)	ballplayer (noun)
(baseball) the person who does the pitching	an athlete who plays baseball
someone who twirls a baton