Incorrectly rank hat as lambskin (9)
I believe the answer is:
astrakhan
'lambskin' is the definition.
(I've seen this before)
'incorrectly rank hat as' is the wordplay.
'incorrectly' indicates an anagram (I've seen this in other clues).
'rank'+'hat'+'as'='rankhatas'
'rankhatas' is an anagram of 'ASTRAKHAN'.
(Other definitions for astrakhan that I've seen before include "Fur - city on Volga" , "Dark tightly-curled wool of Russian lambs" , "Type of fur and Russian city" , "Fur made from tightly-curled lambs wool" , "Lambskin with curled wool" .)