We need to board the train before it leaves.

to get on or into a vehicle, ship, or aircraft.
Please board the bus now.
They will board the plane soon.
We must board the ship.
board the plane
board the train
board the ship
embark
entrain
ascend
The teacher wrote the lesson on the whiteboard.

A flat, rectangular piece of material used for various purposes, such as writing, displaying information, or as a surface for games.
The board is made of wood.
We need a new bulletin board.
He drew a picture on the board.
whiteboard
bulletin board
chalkboard
plank
panel
sheet
We need to board the train before it leaves the station.

To get on or into a vehicle, such as an airplane, train, or ship, for travel.
We will board the plane soon.
Passengers must board now.
They boarded the bus quickly.
board the ship
board the aircraft
board the ferry
embark
entrain
ascend