hitter vs spanker

hitter and spanker both are nouns.

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

As nouns, spanker is a hyponym of hitter; that is, spanker is a word with a more specific, narrower meaning than hitter:

Other hyponyms of hitter include slapper, walloper.

hitter (noun)	spanker (noun)
(baseball) a ballplayer who is batting	a fore-and-aft sail set on the aftermost lower mast (usually the mizzenmast) of a vessel
someone who hits	a hitter who slaps (usually another person) with an open hand