Declare free of guilt (7)
I believe the answer is:
absolve
'declare free of guilt' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for absolve that I've seen before include "Free (a person) from guilt" , "Discharge" , "Set free from guilt" , "Declare (someone) free of guilt" , "Grant remission of a sin" .)