tap dancer vs dancer

tap dancer and dancer both are nouns.

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

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

tap dancer: a dancer who sounds out rhythms by using metal taps on the toes and heels of the shoes
dancer: a performer who dances professionally

Other hypernyms of tap dancer include professional dancer, terpsichorean.

tap dancer (noun)	dancer (noun)
a dancer who sounds out rhythms by using metal taps on the toes and heels of the shoes	a performer who dances professionally
	a person who participates in a social gathering arranged for dancing (as a ball)