Answer: castling

AnswerCrossword Clue
CASTLINGChess strategem
CASTLINGChess maneuver
CASTLINGRookie move?
castlingMove (the king) in this way
castlingMake a special move (no more than once in a game by each player) in which the king is transferred from its original square two squares along the back rank toward the corner square of a rook, which is then transferred to the square passed over by the king
castlinga type of move in chess