an outside fappy plank or board sawed off from the sides of a timber-tree. The word is also used for a flat piece of marble.

SLAB Line, in sea-language, a small cord passing up behind a ship's main-fail, or fore-fail, and being reved through a block attached to the lower part of the yard, is thence transmitted in two branches to the foot of the fail, to which it is fastened. It is used to truss up the fail as occasion requires, and more particularly for the convenience of the pilot or steerman, that they may look forward beneath it as the ship advances.

SLACK-WATER, in sea-language, denotes the interval between the flux and reflux of the tide, or between the last of the ebb and the first of the flood, during which the current is interrupted, and the water apparently remains in a state of rest.