Self-obsession (8)
I believe the answer is:
egomania
'self-obsession' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for egomania that I've seen before include "obsession with self" , "selfish obsession" , "Obsessive self-centredness" , "Extreme self-centredness" , "Thinking of oneself" .)