F distribution n (Statistics) statistics a continuous distribution obtained from the ratio of two chi-square distributions and used esp to test the equality of the variances of two normally distributed variances Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014