An informal unit of volume used in U.S. bartending, equal to 4 (U.S.) fluid ounces or about 118.3 milliliters. This unit is the same as the traditional gill
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}