1. A subsidence of symptoms.
2. A relapse; a return of symptoms.
3. Any retrograde movement or action.
4. A return to a more primitive mode of behavior due to an inability to function adequately at a more adult level.
5. An unconscious defense mechanism by which there occurs a return to earlier patterns of adaptation.
6. The distribution of one random variable given particular values of other variables relevant to it (a formula for the distribution of weight as a function of height and chest circumference). The method was formulated by Galton in his study of quantitative genetics.
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