Abstract: An elastic tongue piece 3 is arranged in an engaging part 2 in which a male terminal 10 can be engaged. The elastic tongue piece 3 is constructed in such a manner that a base end portion 3b is fixed to a backward part of an upper wall of the engaging part 2, and a distal end portion extends forward in the engaging part 2 by way of a curved portion 3c continued from the base end portion 3b. A contact 3a is formed at the distal end portion of the tongue piece 3, and at an intermediate position of the tongue piece 3 between the curved portion 3c and the contact 3a, is provided a fulcrum portion 3d which is in contact with a wall face of a lower wall 2c of the engaging part 2 and slidable with respect to the wall face. The tongue piece 3 is constructed as to be supported at the fulcrum portion 3d against a force in a direction in which the tongue piece is displaced by an insertion of the male terminal.