Fixated (8)
I believe the answer is:
obsessed
'fixated' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for obsessed that I've seen before include "Fanatical" , "With compulsion" , "Compulsively concerned with something" , "with bee in her bonnet?" , "Being excessively concerned with something" .)