rider vs passenger

rider and passenger both are nouns.

Word	Noun	Adjective	Verb	Adverb
rider	Yes	No	No	No
passenger	Yes	No	No	No

As nouns, rider and passenger are synonyms defined as:

rider and passenger: a traveler riding in a vehicle (a boat or bus or car or plane or train etc) who is not operating it

rider (noun)	passenger (noun)
a clause that is appended to a legislative bill	a traveler riding in a vehicle (a boat or bus or car or plane or train etc) who is not operating it
a traveler who actively rides an animal (as a horse or camel)
a traveler riding in a vehicle (a boat or bus or car or plane or train etc) who is not operating it
a traveler who actively rides a vehicle (as a bicycle or motorcycle)