motorbus vs double-decker

motorbus and double-decker both are nouns.

Word	Noun	Adjective	Verb	Adverb
motorbus	Yes	No	No	No
double-decker	Yes	No	No	No

As nouns, motorbus and double-decker are synonyms defined as:

motorbus and double-decker: a vehicle carrying many passengers; used for public transport

Other synonyms of motorbus include autobus, bus, charabanc, coach, jitney, motorcoach, omnibus, passenger vehicle.

motorbus (noun)	double-decker (noun)
a vehicle carrying many passengers; used for public transport	a vehicle carrying many passengers; used for public transport