Jig·ger, n.
 1. One who, or that which, jigs; specifically, a miner who sorts or cleans ore by the process of jigging; also, the sieve used in jigging.
 2. Pottery (a) A horizontal table carrying a revolving mold, on which earthen vessels are shaped by rapid motion; a potter's wheel. (b) A template or tool by which vessels are shaped on a potter's wheel.
 3. Naut. (a) A light tackle, consisting of a double and single block and the fall, used for various purposes, as to increase the purchase on a topsail sheet in hauling it home; the watch tackle. --Totten. (b) A small fishing vessel, rigged like a yawl. [New Eng.] (c) A supplementary sail. See Dandy, n., 2 (b).
 4. A pendulum rolling machine for slicking or graining leather; same as Jack, 4 (i).
 Jigger mast. Naut. (a) The after mast of a four-masted vessel. (b) The small mast set at the stern of a yawl-rigged boat.