break-dance vs break dance

break-dance is not a noun while break dance is a noun.

Word	Noun	Adjective	Verb	Adverb
break-dance	No	No	Yes	No
break dance	Yes	No	Yes	No

As verbs, break-dance and break dance are synonyms defined as:

Other synonyms of break-dance include break.

break-dance (noun)	break dance (noun)
	a form of solo dancing that involves rapid acrobatic moves in which different parts of the body touch the ground; normally performed to the rhythm of rap music

break-dance (verb)	break dance (verb)
do a break dance	do a break dance