What can lubricate? (3,3)
I believe the answer is:
'lubricate?' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'what can' is the wordplay.
'what' becomes 'oil' (I am not sure about this - if you are sure you should believe this answer much more).
Can you help me to learn more?
(Other definitions for oil can that I've seen before include "Lubricant dispenser" , "fuel container" .)