aboard
UK[əˈbɔːd]US[əˈbɔːrd]
prep
on or onto a ship, aircraft, bus, or train
adv
on or onto a ship, aircraft, bus, or train
Morpheme Breakdown
a
board
a
on
board
side of a ship
Etymology
the word 'aboard' is a straightforward compound formed within english. it combines the native prefix 'a-', which denotes position or state, with the noun 'board', which in old english ('bord') specifically referred to the side of a ship. the literal sense was therefore "on the side (or deck) of a ship." over time, as modes of transport evolved, the meaning of 'board' expanded metaphorically to include the deck or interior of any vessel or vehicle, such as a train or aircraft. consequently, 'aboard' generalized from its nautical origins to its current, broader sense of being on or into any public conveyance.
Analysis
Structure: a (on) + board (side of a ship)
a: a prefix of english origin, from old english, meaning "on", "in", or "into".
board: a noun of english origin, from old english 'bord', meaning "side of a ship", later extended to other vehicles.
Examples
welcome aboard the flight to london.
all passengers must be aboard the train ten minutes before departure.
he climbed aboard the bus just as the doors were closing.