1. The state or quality of being identical, or the same; sameness. Identity is a relation between our cognitions of a thing, not between things themselves. (Sir W. Hamilton)
2. The condition of being the same with something described or asserted, or of possessing a character claimed; as, to establish the identity of stolen goods.
3. (Science: mathematics) An identical equation.
Origin: f. Identite, LL. Identitas, fr. L. Idem the same, from the root of is he, that; cf. Skr. Idam this. Cf. Item.