sharpshooter vs sniper

sharpshooter and sniper both are nouns.

Word	Noun	Adjective	Verb	Adverb
sharpshooter	Yes	No	No	No
sniper	Yes	No	No	No

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

Other hyponyms of sharpshooter include deadeye, franc-tireur, rifleman.

sharpshooter (noun)	sniper (noun)
a fast schooner once used by New England fisherman for illegal fishing in Canadian waters	a marksman who shoots at people from a concealed place
someone skilled in shooting
an athlete noted for accurate aim