What is the meaning of Involution?

Entanglement; a spiralling inwards; intricacy.

A complicated grammatical construction.

An endofunction whose square is equal to the identity function; a function equal to its inverse.

The shrinking of an organ (such as the uterus) to a former size.

The regressive changes in the body occurring with old age.

A power: the result of raising one number to the power of another.

A cessation of development or progress despite intense inner competition.

A state of increased competition for limited resources, requiring great effort to stay ahead.

Involution: the migration of a cell layer inward, sliding over an outer layer of cells. Involution occurs at gastrulation during embryogenesis.

Source: wiktionary.org