Tactical move (6)
I believe the answer is:
gambit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tactical move</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for gambit that I've seen before include "Opening chess move" , "Opening move to gain advantage" , "Eg, minestrone" , "tricky move" , "Opening manouevre" .)