Absolve former partner facing single charge (9)
I believe the answer is:
exonerate
'absolve' is the definition.
(thesaurus)
'former partner facing single charge' is the wordplay.
'former partner' becomes 'ex'.
'facing' is a charade indicator (letters next to each other).
'single' becomes 'one' (I've seen this before).
'charge' becomes 'rate' (rate is a kind of charge**).
'ex'+'one'+'rate'='EXONERATE'
(Other definitions for exonerate that I've seen before include "Release" , "Excuse" , "free of charge" , "Acquit" , "Justify" .)