pinch hitter vs batter

pinch hitter and batter both are nouns.

Word	Noun	Adjective	Verb	Adverb
pinch hitter	Yes	No	No	No
batter	Yes	No	Yes	No

As nouns, batter is a hypernym of pinch hitter; that is, batter is a word with a broader meaning than pinch hitter:

Other hypernyms of pinch hitter include batsman, hitter, slugger, reserve, second-stringer, substitute.

pinch hitter (noun)	batter (noun)
(baseball) a substitute for the regular batter	a liquid or semiliquid mixture, as of flour, eggs, and milk, used in cooking
	(baseball) a ballplayer who is batting

pinch hitter (verb)	batter (verb)
	make a dent or impression in
	strike violently and repeatedly
	strike against forcefully