Locking lances (12) are formed at an outer wall (10B) of a housing (10) and are resiliently deformable between engaging positions to engage terminals (20) and disengaging positions outward from the engaging positions to permit the insertion and withdrawal of the terminals (20). Leading end surfaces (12B) of the locking lances (12) are inclined to project gradually forward toward an inner side of the housing (10). A facing surface (15A) of the outer wall (10B) of the housing 10 facing the leading end surfaces (12B) of the locking lances 12 is inclined to project gradually toward the locking lances (12) at more outward positions on the housing (10). The leading end surfaces (12B) of the locking lances (12) contact the facing surface (15A) when the locking lances (12) are deformed outward beyond the disengaging positions.
