[ spon-suh n ]
/ ˈspɒn sən /


a structure projecting from the side or main deck of a vessel to support a gun or the outer edge of a paddle box.
a buoyant appendage at the gunwale of a canoe to resist capsizing.
Aeronautics. a protuberance at the side of a flying-boat hull, designed to increase lateral stability in the water.

Origin of sponson

First recorded in 1825–35; variant of expansion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for sponson

British Dictionary definitions for sponson

/ (ˈspɒnsən) /


navy an outboard support for a gun enabling it to fire fore and aft
a semicircular gun turret on the side of a tank
a float or flotation chamber along the gunwale of a boat or ship
a structural projection from the side of a paddle steamer for supporting a paddle wheel
a structural unit attached to a helicopter fuselage by fixed struts, housing the main landing gear and inflatable flotation bags

Word Origin for sponson

C19: perhaps from expansion
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012