ace vs playing card

ace and playing card both are nouns.

Word	Noun	Adjective	Verb	Adverb
ace	Yes	Yes	Yes	No
playing card	Yes	No	No	No

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

ace (noun)	playing card (noun)
a serve that the receiver is unable to reach	one of a pack of cards that are used to play card games
one of four playing cards in a deck having a single pip on its face
someone who is dazzlingly skilled in any field
the smallest whole number or a numeral representing this number

ace (adjective)	playing card (adjective)
of the highest quality