(psychology) A crisis of personal identity.

(logic) The logical principle that anything equals itself, expressed by the symbolic equation A=A.

plural of identity morphism

plural of identity functor

plural of left identity

(genetics) Of corresponding segments of a chromosome in different individuals, identical because they were inherited from a common ancestor without crossover.

(complex analysis) The equation e^(i𝜋)=-1,!, which unifies diverse fields of mathematics.

(psychiatry) A mental disorder characterized by the presence of two or more personality states or distinct identities that repeatedly take control of a person's behavior.

A condition in which the patient experiences significant gender dysphoria: the diagnostic classification most commonly applied to transgender/transsexual people.

(rare) gender identity disorder