an outside sappy 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-sail, or fore-sail, and being reeved through a block attached to the lower part of the yard, is thence transmitted in two branches to the foot of the sail, to which it is fastened. It is used to tress up the sail as occasion requires, and more particularly for the convenience of the pilot or steersman, 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.