Greg opts to hide pride (3)
I believe the answer is:
ego
'pride' is the definition.
(ego is a kind of pride)
'greg opts to hide' is the wordplay.
'to hide' indicates the answer is hidden within the clue.
'EGO' is hidden in the letters of 'greg opts'.
(Other definitions for ego that I've seen before include "One's image of oneself" , "Self-esteem or self-importance" , "One's self image" , "Self-esteem, conceit" , "Aspect of the personality" .)