Make a certain chess move (6)
I believe the answer is:
castle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">make a certain chess move</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for castle that I've seen before include "Large building; rook" , "Move king to safety - stronghold" , "Imposing residence, perhaps fortified" , "Let sac be a chess piece" , "Fortified place on the chess board" .)