- jigger (n.) "1.5-ounce shot glass," 1836, American English, in early use also of the drink itself, from jigger "illicit distillery" (1824), of unknown origin; or else perhaps from jigger, a 1756 alteration of CHIGGER (Cf. chigger) "tiny mite or flea." As a name for various appliances, the word is attested by 1825, from JIG (Cf. jig).
Etymology dictionary. 2014.