ski jumper vs jumper

ski jumper and jumper both are nouns.

Word	Noun	Adjective	Verb	Adverb
ski jumper	Yes	No	No	No
jumper	Yes	No	No	No

As nouns, jumper is a hypernym of ski jumper; that is, jumper is a word with a broader meaning than ski jumper:

Other hypernyms of ski jumper include skier.

ski jumper (noun)	jumper (noun)
a skier who leaps through the air (especially on a ski jump)	(basketball) a player releases the basketball at the high point of a jump
	a sleeveless dress resembling an apron; worn over other clothing
	a loose jacket or blouse worn by workmen
	a small connector used to make temporary electrical connections
	a coverall worn by children
	a crocheted or knitted garment covering the upper part of the body
	an athlete who competes at jumping
	a person who jumps