A traditional Portuguese unit of liquid volume comparable to 1/2 gallon in the U.S. system. The oitavo equals 1/32 fanega or about 1.73 liters (0.46 U.S. liquid gallon or 0.38 British Imperial gallon)
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}