Jigger n. : A species of flea (Sarcopsylla, / Pulex, penetrans), which burrows beneath the skin. See Chigoe.

Jigger n. & v. : 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.

Jigger n. & v. : A horizontal table carrying a revolving mold, on which earthen vessels are shaped by rapid motion; a potter's wheel.

Jigger n. & v. : A templet or tool by which vessels are shaped on a potter's wheel.

Jigger n. & v. : 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.

Jigger n. & v. : A small fishing vessel, rigged like a yawl.

Jigger n. & v. : A supplementary sail. See Dandy, n., 2 (b).

Jigger n. : A pendulum rolling machine for slicking or graining leather; same as Jack, 4 (i).

Example:
How many ounces are in a Jigger?

Taxonomy
Jigger, free encyclopedia, measure, small fish, mast, search, free dictionary, hook, jerk, see List, hand-operated, railway car, alcoholic beverage, beverage ingredients, parasitic, arthropod, disambiguation pages, chigoe flea.

Defination from the web:
Jigger (bartending), a measure of alcoholic beverage ingredients, and the tool used to measure them. ... The owner of Panathinaikos FC Giannis Vardinogiannis, a former rally driver under the alias "Jigger" An alleyway in Liverpool. The sculpture of a coal miner in Brownhills ...