Full lock receiving portions (31) are provided on a widthwise central part of a housing (10), and partial lock receiving portions (28) are provided on opposite widthwise end parts of the housing (10). Full locking portions (68) configured to prevent a movement of a retainer (60) to a full locking position by coming into contact with a facing wall surface of a housing (10) at a partial locking position and prevent the retainer (60) from returning to the partial locking position by being locked to the full lock receiving portions (31) at the full locking position are provided on a widthwise central part of the retainer (60). Partial locking portions (73) configured to prevent the retainer (60) from coming out of the housing (10) by being locked to the partial lock receiving portions (28) at the partial locking position are provided on opposite widthwise end parts of the retainer (60).