regression
n. C / Un. a return to an earlier, less advanced, or worse state. In math or science, it describes how one thing changes in relation to another.
n. a return to a former or less developed state; in statistics, a functional relationship between two or more variables that allows for prediction.
The patient showed signs of regression after the treatment stopped.
The latest software update caused a regression, breaking several features that had been working perfectly for months.
Linear regression analysis revealed a strong correlation between the amount of rainfall and the annual crop yield, allowing the researchers to model future agricultural outcomes.
Learned borrowing from Latin regressio. Equivalent to regress + -ion. The statistics sense comes from regression to the mean.
Uncountable when referring to the general process of returning to a previous state; countable when referring to specific statistical models or software bugs.