vingt-et-un vs cards

vingt-et-un and cards both are nouns.

Word	Noun	Adjective	Verb	Adverb
vingt-et-un	Yes	No	No	No
cards	Yes	No	No	No

As nouns, cards is a hypernym of vingt-et-un; that is, cards is a word with a broader meaning than vingt-et-un:

vingt-et-un: a gambling game using cards; the object is to hold cards having a higher count than those dealt to the banker up to but not exceeding 21
cards: a game played with playing cards

Other hypernyms of vingt-et-un include card game.

vingt-et-un (noun)	cards (noun)
a gambling game using cards; the object is to hold cards having a higher count than those dealt to the banker up to but not exceeding 21	a game played with playing cards