regression

definition: returning to a former state
example:
speech part: noun
synonyms: reversion
definition: 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)
example:
speech part: noun
synonyms: simple regression regression toward the mean statistical regression
definition: (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state
example:
speech part: noun
synonyms:
definition: an abnormal state in which development has stopped prematurely
example:
speech part: noun
synonyms: fixation arrested development infantile fixation

How regression is being used?