Final layer of paint is worn out (7)
I believe the answer is:
topcoat
This might be a double definition.
'final layer of paint' is the first definition.
(I've seen this before)
'worn out' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'is' is the link.
Can you help me to learn more?
(Other definitions for topcoat that I've seen before include "Heavy winter outer garment" , "Ulster?" , "clothing" , "It's worn on the outside in winter" , "Final layer of paint" .)