parachutist vs skydiver

parachutist and skydiver both are nouns.

Word	Noun	Adjective	Verb	Adverb
parachutist	Yes	No	No	No
skydiver	Yes	No	No	No

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

parachutist: a person who jumps from aircraft using a parachute
skydiver: a person who jumps from a plane and performs various gymnastic maneuvers before pulling the parachute cord

parachutist (noun)	skydiver (noun)
a person who jumps from aircraft using a parachute	a person who jumps from a plane and performs various gymnastic maneuvers before pulling the parachute cord