Doug likes eating fruit (4)
I believe the answer is:
ugli
'fruit' is the definition.
(I know that Ugli is a fruit)
'doug likes eating' is the wordplay.
'eating' says the answer is hidden in the clue.
'UGLI' is hidden in the letters of 'doug likes'.
(Other definitions for ugli that I've seen before include "West Indian citrus fruit" , "Orange-grapefruit cross" , "Cross between Seville orange, grapefruit and tangerine" , "Tangerine-grapefruit hybrid" , "Plain-sounding fruit" .)