A connector mateable with a mating connector which comprises a mating fit portion, wherein: the connector comprises a fixed housing, a movable housing and a plurality of terminals; the terminals are held by the fixed housing and are arranged in a pitch direction; the fixed housing has two sidewalls, two end walls and an accommodation portion; each of the sidewalls extends along the pitch direction; each of the end walls couples the sidewalls with each other in a width direction perpendicular to the pitch direction; the accommodation portion is a space which is enclosed by the sidewalls and the end walls in a horizontal plane defined by the pitch direction and the width direction; each of the end walls has a stopping portion and a projecting portion; each of the stopping portions faces downward in an upper-lower direction perpendicular to both the pitch direction and the width direction; each of the projecting portions projects inward in the pitch direction; the movable housing is movable relative to the fixed housing along the upper-lower direction and is movable relative to the fixed housing along the horizontal plane; the movable housing has a fit portion and a base portion; the fit portion is fit to the mating fit portion under a mated state where the connector and the mating connector are mated with each other; the base portion is located below the fit portion and is, at least in part, accommodated in the accommodation portion; the base portion has two regulated portions which correspond to the end walls, respectively; the regulated portions are located at opposite ends of the base portion in the pitch direction, respectively; each of the regulated portions has a reference surface, a stopped portion and a receiving recess; in each of the regulated portions, the reference surface is located at a position that is outermost in the pitch direction except the stopped portion; each of the stopped portions projects outward in the pitch direction beyond the reference surface and is located below a corresponding one of the stopping portions, and an upward movement thereof is regulated by the corresponding one of the stopping portions; each of the receiving recesses is recessed inward in the pitch direction beyond the reference surface; and each of the receiving recesses faces, at least in part, a corresponding one of the projecting portions in the pitch direction or receives, at least in part, the corresponding one of the projecting portions, characterized in that the stopped portion and the receiving recess of each of the regulated portions are located at positions partially same as each other in the width direction. the connector comprises a fixed housing, a movable housing and a plurality of terminals; the terminals are held by the fixed housing and are arranged in a pitch direction; the fixed housing has two sidewalls, two end walls and an accommodation portion; each of the sidewalls extends along the pitch direction; each of the end walls couples the sidewalls with each other in a width direction perpendicular to the pitch direction; the accommodation portion is a space which is enclosed by the sidewalls and the end walls in a horizontal plane defined by the pitch direction and the width direction; each of the end walls has a stopping portion and a projecting portion; each of the stopping portions faces downward in an upper-lower direction perpendicular to both the pitch direction and the width direction; each of the projecting portions projects inward in the pitch direction; the movable housing is movable relative to the fixed housing along the upper-lower direction and is movable relative to the fixed housing along the horizontal plane; the movable housing has a fit portion and a base portion; the fit portion is fit to the mating fit portion under a mated state where the connector and the mating connector are mated with each other; the base portion is located below the fit portion and is, at least in part, accommodated in the accommodation portion; the base portion has two regulated portions which correspond to the end walls, respectively; the regulated portions are located at opposite ends of the base portion in the pitch direction, respectively; each of the regulated portions has a reference surface, a stopped portion and a receiving recess; in each of the regulated portions, the reference surface is located at a position that is outermost in the pitch direction except the stopped portion; each of the stopped portions projects outward in the pitch direction beyond the reference surface and is located below a corresponding one of the stopping portions, and an upward movement thereof is regulated by the corresponding one of the stopping portions; each of the receiving recesses is recessed inward in the pitch direction beyond the reference surface; and each of the receiving recesses faces, at least in part, a corresponding one of the projecting portions in the pitch direction or receives, at least in part, the corresponding one of the projecting portions, characterized in that the stopped portion and the receiving recess of each of the regulated portions are located at positions partially same as each other in the width direction.