Turn to pulp (4)
I believe the answer is:
mash
'turn to pulp' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mash that I've seen before include "Soft, pulpy mass" , "Pureed potato" , "Brew or infuse (tea)" , "Sham sort of pulp" , "Pummel" .)