aboard: Meaning and Definition of

a•board

1. on board; on, in, or into a ship, train, airplane, bus, etc.: to step aboard.
2. alongside; to the side.
3. on base: a homer with two aboard.
4. (as a warning to passengers entering or planning to enter a train, bus, boat, etc., just before starting) Everyone get on!
5. into a group as a new member: The office manager welcomed him aboard.

1. on board of; on, in, or into: to come aboard a ship.