A suffix added to a number by mathematicians to create units of quantity; a 7-tuple, for example, contains 7 objects, listed in a specified order. The suffix has the same Latin root as -ply, meaning -fold
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}