Regressed

Regressed is the past tense and past participle of the verb regress. The term comes from the Latin regredi, meaning to go back or retreat. In general use, regressed describes a return to a previous state or condition, especially after a period of progress or stability. It may refer to physical change, behavior, or conditions that have diminished or moved backward.

In science and medicine, regressed can describe symptoms that have diminished or receded following treatment or natural course, such as a disease symptom regressing. In coastline or hydrological contexts, a shoreline may regress as land reclaims or water levels change.

In psychology, regression is a defense mechanism in which an individual reverts to an earlier stage of development in response to stress or conflict. Regressed behavior may include infantilism, dependency, or toy-like comfort-seeking; the term "regressed" is used to describe such behavior when it resembles earlier patterns.

In biology, regressed or regressive traits refer to atavisms—ancestral characteristics reappearing after being absent in recent generations. The term is used cautiously, as evolutionary change is complex and claims of reversal are debated.