bulldozer vs tractor

bulldozer and tractor both are nouns.

Word	Noun	Adjective	Verb	Adverb
bulldozer	Yes	No	No	No
tractor	Yes	No	No	No

As nouns, tractor is a hypernym of bulldozer; that is, tractor is a word with a broader meaning than bulldozer:

bulldozer: large powerful tractor; a large blade in front flattens areas of ground
tractor: a wheeled vehicle with large wheels; used in farming and other applications

bulldozer (noun)	tractor (noun)
large powerful tractor; a large blade in front flattens areas of ground	a wheeled vehicle with large wheels; used in farming and other applications
	a truck that has a cab but no body; used for pulling large trailers or vans