rumba vs ballroom dance

rumba and ballroom dance both are nouns.

Word	Noun	Adjective	Verb	Adverb
rumba	Yes	No	Yes	No
ballroom dance	Yes	No	No	No

As nouns, ballroom dance is a hypernym of rumba; that is, ballroom dance is a word with a broader meaning than rumba:

rumba: a ballroom dance based on the Cuban folk dance
ballroom dance: any of a variety of social dances performed by couples in a ballroom

Other hypernyms of rumba include ballroom dancing.

rumba (noun)	ballroom dance (noun)
a folk dance in duple time that originated in Cuba with Spanish and African elements; features complex footwork and violent movement	any of a variety of social dances performed by couples in a ballroom
a ballroom dance based on the Cuban folk dance
syncopated music in duple time for dancing the rumba

rumba (verb)	ballroom dance (verb)
dance the rhumba