skateboard vs skate

skateboard and skate both are nouns.

Word	Noun	Adjective	Verb	Adverb
skateboard	Yes	No	Yes	No
skate	Yes	No	Yes	No

As verbs, skate is a hypernym of skateboard; that is, skate is a word with a broader meaning than skateboard:

skateboard (noun)	skate (noun)
a board with wheels that is ridden in a standing or crouching position and propelled by foot	large edible rays having a long snout and thick tail with pectoral fins continuous with the head; swim by undulating the edges of the pectoral fins
	sports equipment that is worn on the feet to enable the wearer to glide along and to be propelled by the alternate actions of the legs

skateboard (verb)	skate (verb)
ride on a flat board with rollers attached to the bottom	move along on skates