Insensitive state drivers commandeering a single convertible (9)
I believe the answer is:
analgesia
'insensitive state' is the definition.
(analgesia means an inability to feel pain)
'drivers commandeering a single convertible' is the wordplay.
'drivers' becomes 'AA' (Automobile Association).
'commandeering' means one lot of letters goes inside another.
'convertible' indicates an anagram.
'a'+'single'='asingle'
'asingle' anagrammed gives 'nalgesi'.
'aa' enclosing 'nalgesi' is 'ANALGESIA'.
(Other definitions for analgesia that I've seen before include "Inability to feel pain" , "Loss of pain" , "result of medication?" , "As a linage (anag) - insensibility to pain" , "Absence of pain" .)