regress

Short definition from Wiktionary

Noun

1. 1
   The act of passing back; passage back; return; retrogression.
2. 2
   The power or liberty of passing back.
3. 3
   The right of a person (such as a lessee) to return to a property.

Verb

1. 1
   To move backwards to an earlier stage; to devolve.
2. 2
   To move backwards to an earlier stage; to devolve: To re-develop behavior one had previously grown out of, particularly a behavior left behind in childhood.
3. 3
   To move in the retrograde direction.
4. 4
   To reduce in severity or size (as of a tumor), without reaching total remission.
5. 5
   To perform a regression on an explanatory variable.
6. 6
   To interrogate a person in a state of trance about forgotten elements of their past.