a test devised by Karl Pearson that uses the quantity chi-square for testing the mathematical fit of a frequency curve to an observed frequency distribution.

Also chi-squared test[kahy-skwaird]/ˈkaɪˌskwɛərd/.

British Dictionary definitions for chi-square test

chi-square test

noun

statisticsa test derived from the chi-square distribution to compare the goodness of fit of theoretical and observed frequency distributions or to compare nominal data derived from unmatched groups of subjects

A test that uses the chi-square statistic to test the fit between a theoretical frequency distribution and a frequency distribution of observed data for which each observation may fall into one of several classes.