definition of
regression

[1] #1 regression n. [arrested development, fixation, infantile fixation] an abnormal state in which development has stopped prematurely. wn

[2] #2 regression n. (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state. wn

[3] #3 regression n. [simple regression, regression toward the mean, 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). wn

[4] #4 regression n. [regress, reversion, retrogression, retroversion] returning to a former state. wn