Camber
CAMBER, noun Among builders, camber or camber-beam is a piece of timber cut archwise, or with an obtuse angle in the middle, used in platforms, where long and strong beams are required. As a verb, this word signifies to bend, but I know not that it is used.
A cambered-deck, is one which is higher in the middle, or arched, but drooping or declining towards the stem and stern; also, when it is irregular.