regression
UK: rɪˈɡreʃən | US: rɪˈɡreʃən
n. 1. A return to a former or less developed state.
n. 2. (Statistics) A measure of the relationship between variables.
n. 3. (Psychology) Reversion to an earlier mental or behavioral stage.
The word "regression" originates from Latin regressus (a return), formed by combining re- (back) and gradi (to step). The root gress (from gradi) appears in many English words (e.g., "progress," "digress") and consistently conveys movement. The suffix -ion nominalizes the action. The term evolved from literal "stepping backward" to abstract meanings in statistics (19th century) and psychology (20th century), reflecting a logical progression from physical to conceptual retreat.
The patient's regression to childhood behaviors alarmed the therapist.
Linear regression models predict outcomes based on variable relationships.
Economic regression followed the collapse of the trade agreement.
In biology, atavism is a form of evolutionary regression.
The software update caused a regression in system performance.