A unit of quantity equal to 3. The name comes from the Latin trium virum, "of three men," and was first used to describe the governing alliance of Julius Caesar with Pompey the Great and Marcus Licinius Crassus in 60 BCE
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}