Reportedly plain fruit (4)
I believe the answer is:
ugli
'fruit' is the definition.
(ugli is a kind of fruit)
'reportedly plain' is the wordplay.
'reportedly' shows a homophone (sound like).
'plain' becomes 'ugly' (I've seen this before).
'ugly' is a homophone of 'UGLI'.
(Other definitions for ugli that I've seen before include "Tropical fruit" , "Large juicy fruit with thick wrinkled skin" , "Trademarked hybrid citrus fruit" , "Orange-grapefruit cross" , "mixed fruit" .)