(Diagrams) Placing a usually lesser-valued piece in front of a more-valuable one to block its capture by your opponent. Typically used more than not to get your king out of check.
To move a piece between your piece that is threatened and the opponent's piece that is threatening.
Placement of a piece between an attacking enemy queen, rook or bishop, and the piece being attacked.
To place a piece or a Pawn between an enemy attacking piece and the attacked piece.
To move a piece between an attacking piece and its target, blocking the line of attack. Interposing a piece is one of the three possible responses to a check, the others being to move the king or capture the attacking piece.