Definition: a large building formerly occupied by a ruler and fortified against attack
Definition: (chess) the piece that can move any number of unoccupied squares in a direction parallel to the sides of the chessboard
Definition: A large building that is fortified and contains many defences; in previous ages often inhabited by a nobleman or king.
Definition: move the king two squares toward a rook and in the same move the rook to the square next past the king
Definition: To house or keep in a castle.