involution

English

Etymology

From Latin involutio, from volvere ‘to roll’.

Pronunciation

• IPA: /ɪnvəˈluːʃən/
• Rhymes: -uːʃən

Noun

involution (plural involutions)

1. entanglement; a spiralling inwards; intricacy

   • 1968: ‘Gomez,’ said the mortician, ‘is an expert only on the involutions of his own rectum.’ — Anthony Burgess, Enderby Outside

2. (mathematics) An endofunction whose square is equal to the identity function; a function equal to its inverse.
   • 1996, Alfred J. Menezes et al, Handbook of Applied Cryptography, CRC Press, page 10:

     Involutions have the property that they are their own inverses.

3. (physiology) The regressive changes in the body occurring with old age.
4. (mathematics, obsolete) A power: the result of raising one number to the power of another.

Derived terms

• involutional
• involutionary

See also

• dual
• selfdual

Translations

mathematics; an endofunction whose square is equal to the identity function; a function equal to its inverse

• Icelandic: sjálfhverfa (is) f, sjálfhverf vörpun (is) f

• Italian: involuzione (it)