identity

Meanings

1. 1
   noun

   the distinct personality of an individual regarded as a persisting entity

   you can lose your identity when you join the army

2. 2
   noun

   exact sameness

   they shared an identity of interests

3. 3
   noun

   the individual characteristics by which a thing or person is recognized or known

   geneticists only recently discovered the identity of the gene that causes it

4. 4
   noun

   an operator that leaves unchanged the element on which it operates

   the identity under numerical multiplication is 1

5. 5
   noun

   Sameness, identicalness; the quality or fact of (several specified things) being the same.

   But whenas a leſſer number of Agreements in each Paralleliſm (provided there were nothing contrary) could not but have been a ſtrong preſumption of the Identity of the Subjects of the Viſions in each Chapter, I mean, That the Two-horned Beaſt and the Whore are one, and the Seven-headed Beaſt in each Chapter the ſame; how fully aſſured muſt we needs be of theſe Identities, the Agreements of theſe two Paralleliſms (thoſe paſſages onely excepted of which I have given ſo fair an account) perfectly exhauſting the whole ſubſtance of each Chapter?

6. 6
   noun

   The difference or character that marks off an individual or collective from the rest of the same kind; selfhood; the sense of who something or someone or oneself is, or the recurring characteristics that enable the recognition of such an individual or group by others or themselves.

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

7. 7
   noun

   A name or persona—a mask or appearance one presents to the world—by which one is known.

   This criminal has taken on several identities.

8. 8
   noun

   An equation which always holds true regardless of the choice of input variables.

   The equation (x+y)(x−y) = x²−y² is an algebraic identity. It is true regardless of the values of x and y.

Etymology

From Middle English ydemptite, from Middle French identité and its etymon Late Latin idemptitās, identitās, from idem (“the same”) + -tās (suffix forming abstract nouns) as a calque of Ancient Greek ταὐτότης (tautótēs, “sameness”).