The act of involving or infolding.
- The act of involving.
- The state of being involved.
- Intricacy; complexity.
- Something, such as a long grammatical construction, that is intricate or complex.
- Mathematics An operation, such as negation, which, when applied to itself, returns the original number.
- Embryology The ingrowth and curling inward of a group of cells, as in the formation of a gastrula from a blastula.
- Medicine A decrease in size of an organ, as of the uterus following childbirth.
- Medicine A progressive decline or degeneration of normal physiological functioning occurring as a result of the aging process.