involution

plural involutions

1. countableuncountableEntanglement; a spiralling inwards; intricacy.

   ‘Gomez,’ said the mortician, ‘is an expert only on the involutions of his own rectum.’

   1968, Anthony Burgess, “Enderby Outside”, in The Complete Enderby, published 2002, page 302

   1 more example

   […]usually his attention was diverted from her feet by her shrieks of laughter and the astounding involutions of her huge brown-yellow frame.

   1938, Xavier Herbert, chapter V, in Capricornia, page 74

2. countableuncountableA complicated grammatical construction.

   1917, James Huneker, Unicorns, New York: Scribner, Chapter 11 “Style and Rhythm in English Prose,” p. 129, Walter Pater’s essay on Style is honeycombed with involutions and preciosity.

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

   Involutions have the property that they are their own inverses.

   1996, Alfred J. Menezesm, Paul C. van Oorschot, Scott A. Vanstone, Handbook of Applied Cryptography, CRC Press, page 10

4. countableuncountablemedicineThe shrinking of an organ (such as the uterus) to a former size.
5. countableuncountablemedicineThe regressive changes in the body occurring with old age.
6. countableobsoleteuncountablemathematicsA power: the result of raising one number to the power of another.
7. countableuncountableeconomicsA cessation of development or progress involving intense inner competition.
8. countableneologismuncountableA state of increased competition for limited resources, requiring great effort to stay ahead.
9. countableuncountablebiologyThe migration of a cell layer inward, sliding over an outer layer of cells. It occurs at gastrulation during embryogenesis.