passenger
n. countable A2 Elementary Oxford US //ˈpæsəndʒɝ// UK //pˈæsɪndʒɐ// pas·sen·ger
n. a person who is traveling in a vehicle, like a car, bus, or plane, but is not the driver.
n. a person who travels in a conveyance, such as a vehicle, vessel, or aircraft, without participating in its operation.
The bus was full of passengers going to work.
The airline asked all passengers to remain in their seats until the plane reached the gate.
Safety regulations require every passenger to wear a seatbelt, regardless of whether they are seated in the front or the rear of the vehicle.
From Old French passagier with intrusive n (see etymology of messenger).
Usage
Commonly used with the prepositions 'on' for large vehicles like trains or planes, and 'in' for smaller vehicles like cars.