playing card vs spade

playing card and spade both are nouns.

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

As nouns, spade is a hyponym of playing card; that is, spade is a word with a more specific, narrower meaning than playing card:

playing card: one of a pack of cards that are used to play card games
spade: a playing card in the major suit that has one or more black figures on it

playing card (noun)	spade (noun)
one of a pack of cards that are used to play card games	a sturdy hand shovel that can be pushed into the earth with the foot
	a playing card in the major suit that has one or more black figures on it

playing card (verb)	spade (verb)
	dig (up) with a spade