roof vs passenger vehicle

roof and passenger vehicle both are nouns.

Word	Noun	Adjective	Verb	Adverb
roof	Yes	No	Yes	No
passenger vehicle	Yes	No	No	No

roof (noun)	passenger vehicle (noun)
a protective covering that covers or forms the top of a building	a vehicle carrying many passengers; used for public transport
protective covering on top of a motor vehicle
an upper limit on what is allowed
the inner top surface of a covered area or hollow space

roof (verb)	passenger vehicle (verb)
provide a building with a roof; cover a building with a roof