Deboard vs. Unboard

Deboardverb

To exit a form of transportation such as a boat, ship, airplane, trolley, streetcar or spaceship.

‘President Ford fell as he deboarded Air Force One.’; ‘He was detained late Tuesday after deboarding a British Airways flight from London.’;

Unboardverb

(ambitransitive) To leave a passenger vehicle such as a train or ship; to disembark.

Deboardverb

To get off (a train, aeroplane, etc.); to disembark from.

Deboardverb

To get off a train, aeroplane, etc.; to disembark.

Deboardverb

To remove from a train, aeroplane, etc.; to allow (passengers) to disembark.