Battlements are the notched wall along the top of a castle. The wall is built with square “teeth”: the solid bits hide the people behind them, and the gaps are there so they can shoot arrows — and later guns — through. From the ground the top of the castle looks as if every other square has been taken out. You almost always say the plural, battlements, because you mean the whole ring of wall, not one tooth. Today you see them on old castles and on buildings that only want to look like castles; nobody is really shooting from them.

城垛