From Middle English sterbord, stere-bourd, stere-burd, from Old English stēorbord, from Proto-West Germanic *steurubord, equivalent to steer + board (“side (of a ship)”), referring to ancient ships with the steering oar set to the right (to accommodate right-handed crew). Ships had to dock on their left (port) side because the steering oar on the right would get in the way, which is how the left became known as the port side.
- The righthand side of a ship, boat or aircraft when facing the front, or fore or bow. Used to unambiguously refer to directions according to the sides of the vessel, rather than those of a crew member or object.
- (nautical) One of the two traditional watches aboard a ship standing a watch in two.