involution

Meanings

1. Entanglement; a spiralling inwards; intricacy.
2. A complicated grammatical construction.
3. An endofunction whose square is equal to the identity function; a function equal to its inverse.
4. The shrinking of an organ (such as the uterus) to a former size.
5. The regressive changes in the body occurring with old age.
6. A power: the result of raising one number to the power of another.
7. A cessation of development or progress involving intense inner competition.
8. A state of increased competition for limited resources, requiring great effort to stay ahead.
9. The migration of a cell layer inward, sliding over an outer layer of cells. It occurs at gastrulation during embryogenesis.

Etymology

From Latin involūtiō, from involvō.