Doomed fools suffering setback in exploit (8)
I believe the answer is:
destined
'doomed' is the definition.
('destine' can be a synonym of 'doom')
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for destined that I've seen before include "Intended; doomed" , "Didn't see, being fated" , "Fated, fore-ordained" , "Intended (for a particular end)" , "Designated" .)