Sense of self-worth (3)
I believe the answer is:
ego
'sense of self-worth' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ego that I've seen before include "Part of the mind" , "Inflated pride" , "number one" , "Vowel to disappear, < say another" , "Aspect of the personality" .)