Fruit may see small areas full of mould returning (7)
I believe the answer is:
satsuma
'fruit' is the definition.
(I know that satsuma is a fruit)
'small areas full of mould returning' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'areas' becomes 'aa' (two abbreviations for area).
'full of' means one lot of letters goes inside another.
'mould' becomes 'must' (I've seen this before).
'returning' says the letters should be written in reverse.
'aa' enclosing 'must' is 'amusta'.
'amusta' reversed gives 'atsuma'.
's'+'atsuma'='SATSUMA'
'may see' is the link.
(Other definitions for satsuma that I've seen before include "healthy snack" , "Type of tangerine" , "sort of orange" , "Seasonal orange" , "Variety of tangerine" .)