Crossword Genius

Industriously making a vehicle somewhat oily (6)

Ross

I believe the answer is:

busily

I'm a little stuck... Click here to teach me more about this clue!

'industriously' is the definition.
Both the answer and definition are adverbs. Maybe there's a link between them I don't understand?

'a vehicle somewhat oily' is the wordplay.
I cannot really understand how this works, but
'vehicle' could be 'bus' (bus is a kind of vehicle) and 'bus' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

'making' acts as a link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app