starboard (n.)

Old English steorbord, literally "steer-board, side on which a vessel was steered," from steor "rudder, steering paddle," from Proto-Germanic *steuro "a steering" (compare German Steuer), from PIE *steu-, secondary form of root *sta- "to stand, make or be firm," + bord "ship's side" (see board (n.2)). Similar formation in Old Norse stjornborði, Low German stürbord, Dutch stuurboord, German Steuerbord.

Early Germanic peoples' boats were propelled and steered by a paddle on the right side. The opposite side of the ship sometimes in Germanic was the "back-board" (Old English bæcbord). French tribord (Old French estribord), Italian stribordo "starboard" are Germanic loan-words.

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Definitions of starboard from WordNet
starboard (v.)
turn to the right, of helms or rudders;
starboard (n.)
the right side of a ship or aircraft to someone who is aboard and facing the bow or nose;
starboard (adj.)
located on the right side of a ship or aircraft;