gun for hire vs shooter

gun for hire and shooter both are nouns.

Word	Noun	Adjective	Verb	Adverb
gun for hire	Yes	No	No	No
shooter	Yes	No	No	No

As nouns, gun for hire and shooter are synonyms defined as:

Other synonyms of gun for hire include gun, gunman, gunslinger, hired gun, hit man, hitman, torpedo, triggerman.

gun for hire (noun)	shooter (noun)
a professional killer who uses a gun	a large marble used for shooting in the game of marbles
	a person who shoots (usually with respect to their ability to shoot)
	a professional killer who uses a gun
	(sports) a player who drives or kicks a ball at the goal (or a basketball player who shoots at the basket)
	a gambler who throws dice in the game of craps