Forgive a bishop taking crack (7)
I believe the answer is:
absolve
'forgive' is the definition.
(absolving is a kind of forgiving)
'a bishop taking crack' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'taking' is a charade indicator (letters next to each other).
'crack' becomes 'solve' (crack can mean to solve or decipher).
'a'+'b'+'solve'='ABSOLVE'
(Other definitions for absolve that I've seen before include "Exonerate" , "Exculpate" , "Grant pardon for" , "Acquit - free of blame" , "Excuse" .)