pickup truck vs truck

pickup truck and truck both are nouns.

Word	Noun	Adjective	Verb	Adverb
pickup truck	Yes	No	No	No
truck	Yes	No	Yes	No

As nouns, truck is a hypernym of pickup truck; that is, truck is a word with a broader meaning than pickup truck:

Other hypernyms of pickup truck include motortruck.

pickup truck (noun)	truck (noun)
a light truck with an open body and low sides and a tailboard	an automotive vehicle suitable for hauling
	a handcart that has a frame with two low wheels and a ledge at the bottom and handles at the top; used to move crates or other heavy objects

pickup truck (verb)	truck (verb)
	convey (goods etc.) by truck