Homoscedasticity

The condition of equal residual variances in analysis of variance.  It also occurs, for example, when two variables are normally distributed.  Heteroscedasticity, in contrast, occurs when one of the variables is non-normally distributed as in the case of skewness (see figure below). 

A. Homoscedasticity when two variables are normally distributed. B. Heteroscedasticity when one of two variables (x2) is skewed. 

See Analysis of variance (ANOVA)