dancer vs clog dancer

dancer and clog dancer both are nouns.

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

As nouns, clog dancer is a hyponym of dancer; that is, clog dancer is a word with a more specific, narrower meaning than dancer:

dancer: a person who participates in a social gathering arranged for dancing (as a ball)
clog dancer: someone who does clog dancing

Other hyponyms of dancer include dancing partner, folk dancer, raver, waltzer.

dancer (noun)	clog dancer (noun)
a performer who dances professionally	someone who does clog dancing
a person who participates in a social gathering arranged for dancing (as a ball)