lar·board (lär'bərd) n. See port2. adj. On the port side.
[Alteration (influenced by starboard) of Middle English laddebord : perhaps laden, to load; see load + borde, side of a ship; see starboard.]
port 2 (pôrt, pōrt) n. The left-hand side of a ship or aircraft facing forward. Also called larboard. adj. Of, relating to, or on the port. tr. & intr.v.
port·ed, port·ing, ports To turn (a craft) or make a shift to the port side: port the helm; ported sharply to avoid a shoal.
"left-hand side of a ship" (to a person on board and facing the bow), c.1300, ladde-borde, perhaps lit. "the loading side," if this was the side on which goods were loaded onto a ship, from laden "to load" + bord "ship's side." Altered 16c. on influence of starboard, then largely replaced by port (1). to avoid confusion of similar-sounding words. The O.E. term was bæcboard, lit. "back board" (see starboard).