A term used in chess. You say "j'adoube" when you intend to simply adjust the position of a chess piece during a game instead of actually moving it. You are only allowed to reposition the piece firmly in the centre of the same square it was supposed to be on (changing its position is cheating!).
By saying "j'adoube", your opponent knows you are only centering a piece on its square, and are not actually moving it (or taking it, if it is one of his pieces you are adjusting).
Saying "j'adoube" before adjusting a piece is especially important in tournament chess games, where touch move and touch take rules apply.