Nail strategy (4)
I believe the answer is:
tack
I believe this is a double definition.
'nail' is the first definition.
(I know that tack is a type of nail)
'strategy' is the second definition.
(I've seen this in another clue)
(Other definitions for tack that I've seen before include "policy" , "Rubbishy things" , "Turn and sail into the wind" , "Nail; harness" , "Nail; tasteless material" .)