Some of clever ruses go wrong (3)
I believe the answer is:
err
'go wrong' is the definition.
'some of clever ruses' is the wordplay.
'some of' indicates a hidden word.
'ERR' is hidden in the letters of 'clever ruses'.
(Other definitions for err that I've seen before include "Stray from the straight and narrow" , "Miscalculate" , "Go astray" , "Be inaccurate" , "Blunder" .)