who or what somebody or something is
the identity of the victim
the individual characteristics by which a person or thing can be recognized
the condition of being exactly alike; sameness
identity of interests
We speak of two or more distinct objects being ‘identical’ in the sense that they are indistinguishable from one another (five-pence coins, identical twins), even though we know that their similarity is not absolute. In the strict sense identity consists in being the same object, and the question is: when an object that changes in time ceases to be the same. To a person, to keep one's own identity implies memory — Professor Leszek Kołakowski
an algebraic equation that remains true whatever values are substituted for the symbols, e.g. (x + y)2 = x2 + 2xy + y2
= identity operation
= identity element
Aus, NZ a personality or character
He was a well-known television identity
Aus, NZ an eccentric
[early French identité from late Latin identitat-, identitas, from Latin idem same]