Lumpy citrus (4)
I believe the answer is:
ugli
'lumpy citrus' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ugli that I've seen before include "Unattractive-sounding fruit?" , "Citrus fruit of the West Indies" , "Large juicy fruit with thick wrinkled skin" , "Grapefruit/tangerine hybrid" , "mixed fruit" .)