Work with oils (5)
I believe the answer is:
paint
'work with oils' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for paint that I've seen before include "Decorative coating" , "Coloured coating" , "Vividly describe; cosmetic (joc.)" , "Daub" , "Colouring substance" .)