belly dancer vs dancer

belly dancer and dancer both are nouns.

Word	Noun	Adjective	Verb	Adverb
belly dancer	Yes	No	No	No
dancer	Yes	No	No	No

As nouns, dancer is a hypernym of belly dancer; that is, dancer is a word with a broader meaning than belly dancer:

Other hypernyms of belly dancer include professional dancer, terpsichorean.

belly dancer (noun)	dancer (noun)
a woman who performs a solo belly dance	a performer who dances professionally
	a person who participates in a social gathering arranged for dancing (as a ball)