bat boy vs boy

bat boy and boy both are nouns.

Word	Noun	Adjective	Verb	Adverb
bat boy	Yes	No	No	No
boy	Yes	No	No	No

As nouns, boy is a hypernym of bat boy; that is, boy is a word with a broader meaning than bat boy:

bat boy: (baseball) a boy who takes care of bats and other baseball equipment
boy: a youthful male person

Other hypernyms of bat boy include assistant, help, helper, supporter, male child.

bat boy (noun)	boy (noun)
(baseball) a boy who takes care of bats and other baseball equipment	a youthful male person
	(ethnic slur) offensive and disparaging term for Black man
	a friendly informal reference to a grown man
	a male human offspring