volleyball vs court game

volleyball and court game both are nouns.

Word	Noun	Adjective	Verb	Adverb
volleyball	Yes	No	No	No
court game	Yes	No	No	No

As nouns, court game is a hypernym of volleyball; that is, court game is a word with a broader meaning than volleyball:

volleyball: a game in which two teams hit an inflated ball over a high net using their hands
court game: an athletic game played on a court

volleyball (noun)	court game (noun)
a game in which two teams hit an inflated ball over a high net using their hands	an athletic game played on a court
an inflated ball used in playing volleyball