omnibus vs motorcoach

omnibus and motorcoach both are nouns.

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

As nouns, omnibus and motorcoach are synonyms defined as:

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

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

omnibus (noun)	motorcoach (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)	motorcoach (adjective)
providing for many things at once