Pontoon
PONTOON', noun [Latin pons, a bridge, probably from the root of pono, to lay.]
1. A flat-bottomed boat, whose frame of wood is covered and lined with tin, or covered with copper; used in forming bridges over rivers for armies.
2. A lighter; a low flat vessel resembling a barge, furnished with cranes, capstans and other machinery; used in careening ships, chiefly in the Mediterranean.
PONTOON-bridge, is a bridge formed with pontoons, anchored or made fast in two lines, about five feet asunder.
PONTOON-Carriage, is made with two wheels only, and two long side pieces, whose fore ends are supported by timbers.