Fin scratching surface of scale (4)
I believe the answer is:
limb
This might be a double definition.
'fin scratching surface' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'scale' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for limb that I've seen before include "as part of plane, say" , "Eg wing" , "Large tree branch" , "Human's extension" , "Wing, perhaps" .)