OUTRIGGER

n. structure extending from the side of a boat for purposes of stability; stabilizing structure which extends from an aircraft or other vehicle

An outrigger is a part of a boat's rigging which is rigid and extends beyond the side or gunwale of a boat.In an outrigger canoe or bangca and in sailboats such as the proa, an outrigger is a thin, long, solid, hull used to stabilise an inherently unstable main hull. The outrigger is positioned rigidly and parallel to the main hull so that the main hull is less likely to capsize. If only one outrigger is used on a vessel, its weight reduces the tendency to capsize in one direction and its buoyancy reduces the tendency in the other direction.
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Noun
1. a stabilizer for a canoe; spars attach to a shaped log or pontoon parallel to the hull
(hypernym) stabilizer, stabiliser
(part-holonym) outrigger canoe

n. outrigger, structure extending from the side of a boat for purposes of stability; stabilizing structure which extends from an aircraft or other vehicle

(n.)
Any spar or projecting timber run out for temporary use, as from a ship's mast, to hold a rope or a sail extended, or from a building, to support hoisting teckle.
  

(n.)
A projecting support for a rowlock, extended from the side of a boat.
  

(n.)
A projecting contrivance at the side of a boat to prevent upsetting, as projecting spars with a log at the end.
  

(n.)
A boat thus equipped.