Meaning of ABOARD in English

ABOARD

I. a ‧ board 1 /əˈbɔːd $ əˈbɔːrd/ BrE AmE preposition

on or onto a ship, plane, or train:

They finally went aboard the plane.

II. aboard 2 BrE AmE adverb

1 . on or onto a ship, plane, or train:

The plane crashed, killing all 200 people aboard.

The boat swayed as he stepped aboard.

2 . All aboard! spoken used to tell passengers of a ship, bus, or train that they must get on because it will leave soon

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.