■ noun ( plural identities )
1》 the fact of being who or what a person or thing is.
↘the characteristics determining this.
↘[as modifier ] serving to establish the ~ of the owner: an ~ card.
2》 a close similarity or affinity.
3》 Mathematics (also ~ operation ) a transformation that leaves an object unchanged.
↘(also ~ element ) an element of a set which, if combined with another element, leaves that element unchanged.
4》 Mathematics an equation expressing the equality of two expressions for all values of the variables, e.g. ( x + 1) 2 = x 2 + 2 x + 1.
Origin
C16: from late L. identitas , from L. idem 'same'.