One who wrote a lot of nonsense about the tanned skin (7)
I believe the answer is:
leather
'tanned skin' is the definition.
(tanned animal skin)
'one who wrote a lot of nonsense about the' is the wordplay.
'one who wrote a lot of nonsense' becomes 'Lear' (nonsense poet).
'about' is an insertion indicator.
'lear' enclosing 'the' is 'LEATHER'.
(Other definitions for leather that I've seen before include "Animal skins" , "Fabric" , "polish" , "Treated animal skin" , "Flog; hide" .)