Didn’t fail history, say (6)
I believe the answer is:
passed
'didn't fail' is the definition.
(I've seen this in another clue)
'history say' is the wordplay.
'history' becomes 'past' (I've seen this before).
'say' shows a homophone (sound like).
'past' sounds like 'PASSED'.
(Other definitions for passed that I've seen before include "'Brought into effect, laws perhaps (6)'" , "Succeeded" , "Got a good grade" , "Overtook and moved ahead" , "Gone" .)