E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Starboard and Larboard,
Star is the Anglo-Saxon steor, rudder, bord, side; meaning the right side of a ship (looking forwards). Larboard is now obsolete, and port is used instead. To port the helm is to put the helm to the larboard. Byron, in his shipwreck (Don Juan), says of the ship
She gave a heel [i.e. turned on one side], and then a lurch to port,