Cup (c) 3 : An informal unit of volume for coffee. The size of a cup of coffee varies according to local custom, but a typical size is about 5 fluid ounces or 150 milliliters
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}