Twice yearly wife provides fruit (6)
I believe the answer is:
pawpaw
'fruit' is the definition.
(I know that pawpaw is a type of edible fruit)
'twice yearly wife' is the wordplay.
'twice' indicates the doubling of some letters.
'yearly' becomes 'pa' (abbreviation for per annum).
'wife' becomes 'w'.
'pa'+'w'='paw'
'paw' doubled is 'PAWPAW'.
'provides' is the link.
(Other definitions for pawpaw that I've seen before include "foul once" , "Papaya" , "Custard apple tree" , "Fruit" .)