Pickle to grate for container (6)
I believe the answer is:
jamjar
'container' is the definition.
(jamjar is a kind of container)
'pickle to grate' is the wordplay.
'pickle' becomes 'jam' ('jam' can be a synonym of 'pickle').
'to grate' becomes 'jar' (I've seen this before).
'jam'+'jar'='JAMJAR'
'for' acts as a link.
(Other definitions for jamjar that I've seen before include "Glass container" , "Container for preserve" , "London Transport?" , "Vessel" , "Container for conserve" .)