crown prince vs prince

crown prince and prince both are nouns.

Word	Noun	Adjective	Verb	Adverb
crown prince	Yes	No	No	No
prince	Yes	No	No	No

As nouns, prince is a hypernym of crown prince; that is, prince is a word with a broader meaning than crown prince:

crown prince: a male heir apparent to a throne
prince: a male member of a royal family other than the sovereign (especially the son of a sovereign)

crown prince (noun)	prince (noun)
a male heir apparent to a throne	a male member of a royal family other than the sovereign (especially the son of a sovereign)