omnibus vs roof

omnibus and roof both are nouns.

Word	Noun	Adjective	Verb	Adverb
omnibus	Yes	Yes	No	No
roof	Yes	No	Yes	No

omnibus (noun)	roof (noun)
a vehicle carrying many passengers; used for public transport	a protective covering that covers or forms the top of a building
an anthology of articles on a related subject or an anthology of the works of a single author	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

omnibus (adjective)	roof (adjective)
providing for many things at once

omnibus (verb)	roof (verb)
	provide a building with a roof; cover a building with a roof