Answer: seatmate

AnswerCrossword Clue
SEATMATEBus-ride companion
SEATMATEFellow traveler
SEATMATEFellow chairperson?
SEATMATENext one in a row
SEATMATEOne next to you on a plane, e.g.
SEATMATECompetitor for an armrest
seatmateperson who shares a seat or occupies the seat next to oneself on a bus, plane, etc.
seatmateone with whom one shares a seat