Turn scoundrel going after wife (5)
I believe the answer is:
wheel
'turn' is the definition.
(thesaurus)
'scoundrel going after wife' is the wordplay.
'scoundrel' becomes 'heel' (heel is a kind of scoundrel).
'going after' says to put letters next to each other.
'wife' becomes 'w'.
'heel' after 'w' is 'WHEEL'.
(Other definitions for wheel that I've seen before include "Circular object (in no need of re-invention!)" , "Circular structure on axle" , "ring" , "Circular steering device" , "Change direction as if on an axis" .)