motorbus vs autobus

motorbus and autobus both are nouns.

Word	Noun	Adjective	Verb	Adverb
motorbus	Yes	No	No	No
autobus	Yes	No	No	No

As nouns, motorbus and autobus are synonyms defined as:

motorbus and autobus: a vehicle carrying many passengers; used for public transport

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

motorbus (noun)	autobus (noun)
a vehicle carrying many passengers; used for public transport	a vehicle carrying many passengers; used for public transport