Unattractive-sounding fruit (4)
I believe the answer is:
ugli
'unattractive-sounding fruit' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ugli that I've seen before include "Citrus fruit cross (which sounds offensive!)" , "Plain-sounding fruit" , "Sweet variety of tangelo from Jamaica" , "(Repulsive-looking?) fruit" , "Black/violet element" .)