Promise confidence (9)
I believe the answer is:
assurance
I believe this is a double definition.
'promise' is the first definition.
(assurance is a kind of promise)
'confidence' is the second definition.
(synonyms)
(Other definitions for assurance that I've seen before include "Confidence, certainty" , "Cure an ass of a feeling of certainty" , "Guarantee - belief in oneself" , "what may follow life" , "Confidence (in abilities)" .)