Jamaican citrus fruit (4)
I believe the answer is:
ugli
'jamaican citrus fruit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ugli that I've seen before include "Cross between Seville orange, grapefruit and tangerine" , "Black/violet element" , "Grapefruit/tangerine hybrid" , "Hybrid of tangerine and grapefruit" , "Citrus fruit cross (which sounds offensive!)" .)