- a structure that projects from the side of a ship or boat; specif.,
- a projecting gun platform
- an air chamber built into the gunwale of a canoe
- a short, winglike piece attached to the hull of a seaplane just above water level to give stability in the water
Origin of sponsonaltered from uncertain or unknown; perhaps expansion: origin, originally applied to the platforms on each side of a steamer's paddle wheels
- Any of several structures that project from the side of a boat or ship, especially a gun platform.
- A short, curved, air-filled projection on the hull of a seaplane, imparting stability in the water.
Origin of sponsonPerhaps alteration of expansion