Wheatsheaf provides grub (4)
I believe the answer is:
eats
'grub' is the definition.
(I know that grub can be written as eats)
'wheatsheaf provides' is the wordplay.
'provides' indicates a hidden word.
'EATS' is hidden in the letters of 'wheatsheaf'.
(Other definitions for eats that I've seen before include "Consumes with teas" , "Takes nourishment" , "Food (informal)" , "Seat (anag.)" , "worries" .)