Entire sum is said to be salutary (9)
I believe the answer is:
wholesome
'salutary' is the definition.
(thesaurus)
'entire sum is said' is the wordplay.
'entire' becomes 'whole' (similar in meaning).
'is said' shows a homophone (sound like).
'sum' sounds like 'some'.
'whole'+'some'='WHOLESOME'
'to be' is the link.
(Other definitions for wholesome that I've seen before include "Good for you!" , "Respectable" , "Healthy in body, taste or morals" , "Moral" , "Previously propitious" .)