now called port (q.v.). (Starboard is from Anglo-Saxon steorabord, the steer-board, or right side of a ship.) Larboard is the French bâbord, the left-hand side of a ship looking towards the prow;
She gave a heel, and then a lurch to port, And going down head foremost- sunk in short.
“To give a heel” is to sway over on one side. Here it means a heel to the starboard side.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894