from
The Collaborative International Dictionary of English v.0.48
Pontoon \Pon*toon"\, n. [F. ponton (cf. It. pontone), from L.
ponto, -onis, fr. pons, pontis, a bridge, perhaps originally,
a way, path: cf. Gr. ? path, Skr. path, pathi, panthan. Cf.
{Punt} a boat.]
1. (Mil.) A wooden flat-bottomed boat, a metallic cylinder,
or a frame covered with canvas, India rubber, etc.,
forming a portable float, used in building bridges quickly
for the passage of troops.
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2. (Naut.) A low, flat vessel, resembling a barge, furnished
with cranes, capstans, and other machinery, used in
careening ships, raising weights, drawing piles, etc.,
chiefly in the Mediterranean; a lighter.
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{Pontoon bridge}, a bridge formed with pontoons.
{Pontoon train}, the carriages of the pontoons, and the
materials they carry for making a pontoon bridge.
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Note: The French spelling ponton often appears in scientific
works, but pontoon is more common form.
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