Bart Simpson's father (5)
I believe the answer is:
homer
'bart simpson's father' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for homer that I've seen before include "Trained pigeon" , "Greek poet, c. 800 BC" , "Weak official" , "Epic poet - score at baseball - kind of pigeon" , "Great Greek poet of the Iliad and the Odyssey" .)