outrigger

noun

1. a framework extended outboard from the side of a boat, especially, as in South Pacific canoes, supporting a float that gives stability.
2. a bracket extending outward from the side of a racing shell, to support an oarlock.
3. the shell itself.
4. a spar rigged out from a ship’s rail or the like, as for extending a sail.
5. a long, flexible rod, attached to a fishing boat near the stern, along which a fishing line may be threaded to keep it clear of the boat’s wake when trolling.
6. a structure extending outward from a vehicle, vessel, or aircraft to increase stability or provide support for something.
7. a projecting beam, as for supporting a hoisting tackle.
8. a horizontal steel beam extending the base of a crane.

noun

1. a framework for supporting a pontoon outside and parallel to the hull of a boat to provide stability
2. a boat equipped with such a framework, esp one of the canoes of the South Pacific
3. any projecting framework attached to a boat, aircraft, building, etc, to act as a support
4. rowing another name for rigger (def. 2)

n.device used in Pacific and Indian oceans to stabilize canoes, 1748, altered (by influence of rig) from outligger (late 15c.) “a spar projecting from a vessel,” probably from the same root as Dutch uitlegger, literally “out-lyer.”