In the Black Forest area, it's very dark (3)
I believe the answer is:
tar
'very dark' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'in the black forest area' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TAR' is hidden in the letters of 'black forest area'.
'it's' is the link.
Can you help me to learn more?
(Other definitions for tar that I've seen before include "Sticky substance used in road construction" , "Sticky cigarette residue" , "Sailor; road surface" , "It paves the way" , "Sailor; bitumen" .)