Didn't succeed (6)
I believe the answer is:
failed
'didn't succeed' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for failed that I've seen before include "Bankrupt" , "Did not succeed, perhaps at exam" , "Didn't make it - not well" , "Was unsuccessful, did not pass exam" , "Didn't succeed" .)