Course of action (4)
I believe the answer is:
tack
'course of action' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tack that I've seen before include "pin" , "Ship's course; horse's harness" , "(Of a sailing ship) alter course through the wind" , "Drawing-pin" , "Nail - windward course - temporary stitch" .)