regression re·gres·sion (rĭ-grěsh'ən)
A subsidence of the symptoms of a disease.
A relapse of symptoms.
Reversion to an earlier or less mature pattern of feeling or behavior.
Relapse to a less perfect or developed state.
The return of a population to an earlier or less complex physical type in successive generations.
The relationship between the mean value of a random variable and the corresponding values of one or more independent variables.