Firm belief in record blemish? (10)
I believe the answer is:
conviction
'firm belief' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for conviction that I've seen before include "that may lead to imprisonment?" , "Certainty" , "Firm belief" , "it follows proof of guilt" , "in being found guilty" .)