Today's word of the day is "regression."

Regression

1. the act of going back to a previous place or state; return or reversion.
2. retrogradation; retrogression.
3. Biology. reversion to an earlier or less advanced state or form or to a common or general type.
4. Psychoanalysis. 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.