(statistics) An equation using specified and associated data for two or more variables such that one variable can be estimated from the remaining variable(s).

(programming) The reappearance of a bug in a piece of software that had previously been fixed.

(medicine) The diminishing of a cellular mass like a tumor, or of an organ size.

“The regressand in this study is the annual household income, while the independent variables include level of education and years of work experience.”

“The White procedure corrects for problems arising from the variance of the error term being heteroskedastic as well as correlated with the regressors.”