Everyone who learns that the little double-sided cone used to measure a shot is called a jigger has a reaction of disbelief. Is this a bad joke? But no, alas, common terminology has all bar tenders of America measuring hard liquor for our cocktails in jiggers. The most likely etymology of this term points to the word chigger, a common parasite. Since the jigger is the smallest measurement of liquid commonly found in a kitchen, just 1.5 ounces, it shares its name with the tiny mite. Jigger is also used to describe the smallest mast on sailing ships, known as the jiggermast. So it seems that chigger, started meaning things that are small, like the mite, and changed to the word jigger.