Fools set up with trap good for robbing (8)
I believe the answer is:
stinging
'robbing' is the definition.
'fools set up with trap good' is the wordplay.
'fools' becomes 'nits' (I've seen this in other clues**).
'set up' shows that the letters should be reversed in order.
'with' means one lot of letters go next to another.
'trap' becomes 'gin' (I've seen this before).
'good' becomes 'g' (abbreviation).
'nits' in reverse letter order is 'stin'.
'stin'+'gin'+'g'='STINGING'
'for' is the link.
(Other definitions for stinging that I've seen before include "Biting, as a wasp" , "Producing a sharp tingling pain" , "creating irritation" .)