Cheat, having succeeded, gloated (5)
I believe the answer is:
screw
'cheat' is the definition.
(I know that cheat can be written as screw)
'succeeded gloated' is the wordplay.
I cannot quite see how this works, but
'succeeded' could be 's' (genealogical abbreviation) and 's' is present in the answer.
The remaining letters 'crew' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'having' is the link.
Can you help me to learn more?
(Other definitions for screw that I've seen before include "may need a driver" , "Fastener; propeller" , "Prison officer (slang)" , "Fastener, rivet" , "wages" .)