board verb definition in Plane travel topic from the Oxford Advanced Learner's Dictionary

board

 verb: Plane travel topic
1 [intransitive, transitive] (formal) to get on a ship, train, plane, bus, etc. Passengers are waiting to board. board something The ship was boarded by customs officials.2 [intransitive] be boarding when a plane or ship is boarding, it is ready for passengers to get on Flight BA193 for Paris is now boarding at Gate 37.