identity

noun

1. the distinct personality of an individual regarded as a persisting entity

   noun.attribute

   Examples

   You can lose your identity when you join the army.

   Synonyms individuality personal identity

   Source: WordNet 3.0

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

   noun.cognition

   Examples

   Geneticists only recently discovered the identity of the gene that causes it.

   It was too dark to determine his identity.

   She guessed the identity of his lover.

   Source: WordNet 3.0

3. an operator that leaves unchanged the element on which it operates

   noun.linkdef

   Examples

   The identity under numerical multiplication is 1.

   Synonyms identity element identity operator

   Source: WordNet 3.0

4. exact sameness

   noun.attribute

   Examples

   They shared an identity of interests.

   Synonyms identicalness indistinguishability

   Source: WordNet 3.0

5. The state or quality of being identical, or the same; sameness.

   noun

   Source: webster1913