One's individuality (8)
I believe the answer is:
identity
'one's individuality' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for identity that I've seen before include "Individuality or singularity" , "sort of card" , "Specified name of description of tin deity" , "The question of who one is" , "it may precede crisis" .)