nonidentity

noun

non·​iden·​ti·​ty ˌnän-ī-ˈden-tə-tē 

-ə-,

-ˈde-nə-

: the condition of not being the same one that is described or asserted : lack of identity

These cases may be illustrated by the complete identity of the morning star with the evening star, on the one hand, and the complete nonidentity of the morning star with the Red Planet [=Mars], on the other.

—D. M. Armstrong

Word History

First Known Use

1808, in the meaning defined above