crap-shooter vs gambler

crap-shooter and gambler both are nouns.

Word	Noun	Adjective	Verb	Adverb
crap-shooter	Yes	No	No	No
gambler	Yes	No	No	No

As nouns, gambler is a hypernym of crap-shooter; that is, gambler is a word with a broader meaning than crap-shooter:

crap-shooter: a gambler who throws dice in the game of craps
gambler: a person who wagers money on the outcome of games or sporting events

crap-shooter (noun)	gambler (noun)
a gambler who throws dice in the game of craps	a person who wagers money on the outcome of games or sporting events
	someone who risks loss or injury in the hope of gain or excitement