One who wrote nonsense about the kid, perhaps (7)
I believe the answer is:
Here is my best explanation:
This clue might be a double definition.
'one who wrote nonsense' is the first definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'the kid perhaps' is the second definition.
(kid is a kind of leather)
'about' is the link.
(Other definitions for leather that I've seen before include "Dressed skin", "A tanned hide", "Polishing cloth", "Hide", "Animal skins", "Fabric", "Flog; hide", "Cured animal hide", "Dressed hide" and "A tanner produces it from hide".)