autobus vs motorcoach

autobus and motorcoach both are nouns.

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

As nouns, autobus and motorcoach are synonyms defined as:

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

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

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