What can be used for lubricating? (6)

I believe the answer is:

oilcan

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'used for lubricating?' is the definition.
I can't judge whether this defines the answer.

'what can' is the wordplay.
'what' becomes 'oil' (I can't justify this - if you can you should believe this answer much more).
'oil'+'can'='OILCAN'

'be' acts as a link.

Can you help me to learn more?

(Other definitions for oilcan that I've seen before include "Vessel for lubricant" , "Lubricator with a long nozzle" , "Lubricant applier" , "item found in the garage" , "Vessel for viscous liquid" .)

I've seen this clue in the Evening Standard.

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