picador vs horseback rider

picador and horseback rider both are nouns.

Word	Noun	Adjective	Verb	Adverb
picador	Yes	No	No	No
horseback rider	Yes	No	No	No

As nouns, horseback rider is a hypernym of picador; that is, horseback rider is a word with a broader meaning than picador:

picador: the horseman who pricks the bull with a lance early in the bullfight to goad the bull and to make it keep its head low
horseback rider: a person skilled in equitation

Other hypernyms of picador include bullfighter, toreador, equestrian.

picador (noun)	horseback rider (noun)
the horseman who pricks the bull with a lance early in the bullfight to goad the bull and to make it keep its head low	a person skilled in equitation