1. returning to a former state
Synonym: regressreversionretrogressionretroversion
2. the relation between selected values of x and observed values of y (from which the most probable value of y can be predicted for any value of x)
Synonym: simple regressionregression toward the meanstatistical regression
3. (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state
4. an abnormal state in which development has stopped prematurely