The collective aspect of the set of characteristics by which a thing is definitively recognizable or known: "If the broadcast group is the financial guts of the company, the news division is its public identity\u201d ( Bill Powell). The set of behavioral or personal characteristics by which an individual is recognizable as a member of a group. The quality or condition of being the same as something else. The distinct personality of an individual regarded as a persisting entity; individuality. Information, such as an identification number, used to establish or prove a person's individuality, as in providing access to a credit account. Mathematics An equation that is satisfied by any number that replaces the letter for which the equation is defined. Mathematics Identity element.