Inability to feel pain (9)
I believe the answer is:
analgesia
'inability to feel pain' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for analgesia that I've seen before include "Painlessness" , "Absence of pain" , "As a linage (anag) - insensibility to pain" , "The relief of pain by drugs" , "No hard feelings" .)