slugger vs hitter

slugger and hitter both are nouns.

Word	Noun	Adjective	Verb	Adverb
slugger	Yes	No	No	No
hitter	Yes	No	No	No

As nouns, slugger and hitter are synonyms defined as:

Other synonyms of slugger include batsman, batter.

slugger (noun)	hitter (noun)
(baseball) a ballplayer who is batting	(baseball) a ballplayer who is batting
a boxer noted for an ability to deliver hard punches	someone who hits