Tactic (4)
I believe the answer is:
ploy
'tactic' is the definition.
(a ploy is a tactic or scheme)
This is the entire clue.
(Other definitions for ploy that I've seen before include "Ruse or gimmick" , "Tactical scheme" , "Cunning tactic" , "Cunning manoeuvre to gain advantage" , "Ruse, stratagem" .)