Healing claimed in treatment (9)
I believe the answer is:
medicinal
'healing' is the definition.
(I've seen this before)
'claimed in treatment' is the wordplay.
'treatment' indicates anagramming the letters.
'claimed'+'in'='claimedin'
'claimedin' is an anagram of 'MEDICINAL'.
(Other definitions for medicinal that I've seen before include "Having healing properties" , "concerning drugs" , "Lily 15's invention" , "analeptic" , "With therapeutic properties" .)