Usually bad reason (6)
I believe the answer is:
motive
This clue could be a double definition.
'usually bad' is the first definition.
Both the answer and definition are adjectives. Maybe there's a link between them I don't understand?
'reason' is the second definition.
(I've seen this in another clue)
Can you help me to learn more?
(Other definitions for motive that I've seen before include "Rationale, purpose" , "Reason for doing something, say murder" , "Purpose - reason" , "Ground" , "Reason (for acting)" .)