definition of
castle

[1] #1 castle n. [palace] a large and stately mansion. wn

[2] #2 castle n. a large building formerly occupied by a ruler and fortified against attack. wn

[3] #3 castle v. move the king two squares toward a rook and in the same move the rook to the square next past the king. wn

[4] #4 castle n. [rook] (chess) the piece that can move any number of unoccupied squares in a direction parallel to the sides of the chessboard. wn

[5] #5 castle n. [castling] interchanging the positions of the king and a rook. wn