Go crazy after retirement (4)
I believe the answer is:
stab
'go' is the definition.
(both can mean an attempt)
'crazy after retirement' is the wordplay.
'crazy' becomes 'bats' (I've seen this before).
'after retirement' is a reversal indicator.
'bats' in reverse letter order is 'STAB'.
(Other definitions for stab that I've seen before include "Puncture" , "Go" , "Injure with knife" , "It could be the death of you" , "effort" .)