regression in WordNet English dictionary

1. an abnormal state in which development has stopped prematurely
   arrested development  fixation  infantile fixation  regression 
   
2. returning to a former state
   regression  regress  reversion  retrogression  retroversion 
   
3. 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)
   regression  simple regression  regression toward the mean  statistical regression 
   
4. (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state
   regression