Milk can (5)
I believe the answer is:
churn
'milk can' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for churn that I've seen before include "Butter-making machine" , "Agitate - milk container" , "Kind of barrel in which butter in made" , "Machine in which milk is beaten to make butter" , "boil" .)