Slap on the wrist from bishop most unlikely (5)
I believe the answer is:
blast
'slap on the wrist' is the definition.
(both can mean a rebuke)
'bishop most unlikely' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'most unlikely' becomes 'last' (I've seen this before).
'b'+'last'='BLAST'
'from' acts as a link.
(Other definitions for blast that I've seen before include "Mild expletive - sharp explosion" , "Sudden, strong current of air" , "slate" , "Shoot" , "Report" .)