card shark vs grifter

card shark and grifter both are nouns.

Word	Noun	Adjective	Verb	Adverb
card shark	Yes	No	No	No
grifter	Yes	No	No	No

As nouns, grifter is a hypernym of card shark; that is, grifter is a word with a broader meaning than card shark:

card shark: a professional card player who makes a living by cheating at card games
grifter: a person who swindles you by means of deception or fraud

Other hypernyms of card shark include card player, chiseler, chiseller, defrauder, gouger, scammer, swindler.

card shark (noun)	grifter (noun)
a professional card player who makes a living by cheating at card games	a person who swindles you by means of deception or fraud