Involute: 1. Literally, to turn inward or roll inward. 2. To decrease in size after an enlargement. The uterus involutes after pregnancy. The thymus involutes after adolescence. 3. To undergo a retrograde change. After treatment, a tumor may involute. 4. To shrink physically and emotionally with advancing age.
From the Latin involutio, from in- meaning into + volvere meaning to roll.