identity

Middle French identité, from Latin idem (“the same”). See identical and idem.

• IPA^(key): /aɪˈdɛntəti/

• Audio (AU)

  (file)

identity (countable and uncountable, plural identities)

1. Sameness, identicalness; the quality or fact of (several specified things) being the same.
   • 1997, Hydrothermal Vent Fauna, in Advances in Marine Biology: The Biogeography of the Oceans, page 111:

     […] suggesting the two are different stages of the same species. The identity of the two species is further suggested by allozyme analysis […]

2. The difference or character that marks off an individual from the rest of the same kind, selfhood.
   • (The addition of quotations indicative of this usage is being sought):
3. A name or persona—the mask or appearance one presents to the world—by which one is known.

   This criminal has taken on several identities.

4. Sense of who one is.

   I've been through so many changes, I have no sense of identity.

   This nation has a strong identity.

5. (algebra, computing) Any function which maps all elements of its domain to themselves.
6. (algebra) An element of an algebraic structure which, when applied to another element under an operation in that structure, yields this second element.
7. (Australia, New Zealand) A well-known or famous person.
   • 1887 July 19, "Drowned at Williamstown", The Age (Melbourne)

     The body of a well known old identity named James Conroy […] was found in the water yesterday afternoon…

   • 2013 April 4, "Cricket identities consult lawyers", New Zealand Herald
   • 2016 January 13, "Kings Cross identities arrested in connection with murder", The Sydney Morning Herald

• (sameness): See also Thesaurus:sameness
• (difference that marks off an individual): individuality, selfhood; see also Thesaurus:selfhood
• (mathematics): identity function
• (famous person): celebrity, personality

• identity in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• identity in The Century Dictionary, New York, N.Y.: The Century Co., 1911.