regression, regression toward the mean, simple regression, statistical regression - 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)

regress, regression, retrogression, retroversion, reversion - returning to a former state

arrested development, fixation, infantile fixation, regression - an abnormal state in which development has stopped prematurely

regression - (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state

Source : WordNet