From Longman Dictionary of Contemporary Englishjiggerjig‧ger /ˈdʒɪɡə $ -ər/ noun [countable] DFDa unit for measuring alcohol, equal to one and a half ounces, or the small glass this is measured with
Examples from the Corpus
jigger• Vi McKeown knew every back street and jigger north of the Liver Building, and she would get there.• Mr Braithwaite drained off his lime squash and added a couple of jiggers of rum to his empty glass.• We better add two more strands to the jigger. 