Pronunciation: (ri-gresh'un),[key] —n. 1. the act of going back to a previous place or state; return or reversion.
2. retrogradation; retrogression.
3. Biol.reversion to an earlier or less advanced state or form or to a common or general type.
4. Psychoanal.the reversion to a chronologically earlier or less adapted pattern of behavior and feeling.
5. a subsidence of a disease or its manifestations: a regression of symptoms.
—adj. of, pertaining to, or determined by regression analysis: regression curve; regression equation.