operatic star vs vocalist

operatic star and vocalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
operatic star	Yes	No	No	No
vocalist	Yes	No	No	No

As nouns, vocalist is a hypernym of operatic star; that is, vocalist is a word with a broader meaning than operatic star:

Other hypernyms of operatic star include singer, vocaliser, vocalizer.

operatic star (noun)	vocalist (noun)
singer of lead role in an opera	a person who sings