Not the last painting where a polar bear is black (9)
I believe the answer is:
undercoat
'black' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for undercoat that I've seen before include "tin of paint?" , "The first layer of paint" .)
