Relieve, mitigate (9)
I believe the answer is:
alleviate
This clue is a double definition.
'relieve' is the first definition.
(synonyms)
'mitigate' is the second definition.
(thesaurus)
(Other definitions for alleviate that I've seen before include "Make less severe, say suffering" , "Lessen severity" , "bring relief" , "Make (suffering etc) easier to bear" , "To mollify" .)