omnibus vs passenger vehicle

omnibus and passenger vehicle both are nouns.

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

As nouns, omnibus and passenger vehicle are synonyms defined as:

omnibus and passenger vehicle: a vehicle carrying many passengers; used for public transport

Other synonyms of omnibus include autobus, bus, charabanc, coach, double-decker, jitney, motorbus, motorcoach.

omnibus (noun)	passenger vehicle (noun)
a vehicle carrying many passengers; used for public transport	a vehicle carrying many passengers; used for public transport
an anthology of articles on a related subject or an anthology of the works of a single author

omnibus (adjective)	passenger vehicle (adjective)
providing for many things at once