Bear the onset of bankruptcy before downfall (5)
I believe the answer is:
bruin
'bear' is the definition.
(I've seen this before)
'the onset of bankruptcy before downfall' is the wordplay.
'the onset of' suggests taking the first letters.
'before' is a charade indicator (letters next to each other).
'downfall' becomes 'ruin' (I've seen this before).
The first letter of 'bankruptcy' is 'b'.
'b'+'ruin'='BRUIN'
(Other definitions for bruin that I've seen before include "Archetypal name for a bear" , "Conventional name for a bear" .)