Definition of: regression

(ri·gresh′ən) noun
1. The act of moving back or returning.
2. Astron. Motion in a direction opposite to that of the general motion of the heavenly bodies.
3. Psychoanal. A retreat of the libido to earlier levels of development or to infantile tendencies belonging to a period preceding the obstacles which prevented their normal fulfilment.
4. Stat. The return to a mean or average value.
5. Med. The subsidence of a disease or of its symptoms.