Generally, regression is a move backwards. Specifically:
A term for the exploring, with the assistance of a therapist, of (possibly unpleasant) past memories as part of the treatment for mental illnesses. See psychotherapy, hypnotherapy.
The phenomenon that, when two related variables are measured, the expected value of the second is closer to the mean than the measured value of the first. See regression toward the mean.
... size is 2.77.
In the village the population is spread out with 17.4% under the age of 18, 3.5% from 18 to 24, 22.3% from 25 to 44, 28.7% from 45 to 64, and 28.1% who ...