Downfall of bear without capital (4)
I believe the answer is:
ruin
'downfall' is the definition.
(thesaurus)
'bear without capital' is the wordplay.
'bear' becomes 'bruin' (bruin is a kind of bear).
'without capital' means to remove the first letter.
'bruin' with its initial letter taken off is 'RUIN'.
'of' acts as a link.
(Other definitions for ruin that I've seen before include "Disaster, collapse" , "financial disaster" , "financial hardship" , "Building remains" , "Wrecked building" .)