Struggles to take top off paint (4)
I believe the answer is:
oils
'paint' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for oils that I've seen before include "Viscous substances kept in silo" , "Lubricates; paints" , "Reduces friction" , "art exhibits perhaps" , "Lubricants stored in silo" .)