Rooks (7)
I believe the answer is:
castles
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rooks</span>' is the definition.<br/ ><span class="explanation-format__explanation">('castle' can be a synonym of 'rook')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for castles that I've seen before include "Large and stately mansions" , "Men" , "Keeps" , "buildings" , "pieces for chess board" .)