charabanc vs autobus

charabanc and autobus both are nouns.

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

As nouns, charabanc and autobus are synonyms defined as:

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

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

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