Definition of sponson
1a : a projection (as a gun platform) from the side of a ship or a tankb : an air chamber along a watercraft (as a canoe) to increase stability and buoyancy
2 : a light air-filled structure or a winglike part protruding from the hull of a seaplane to steady it on water
Origin of sponson
perhaps by shortening & alteration from expansion
First Known Use: 1835
Seen and Heard
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