mansard

The upper story formed by the lower slope of a mansard roof.

In French, a mansard roof; a dormer-window; hence, a chamber lighted by such a window; a chamber in the roof: in English used in all these senses. See Mansard roof, under roof.

having two slopes on each side, the lower being steeper than the upper

A mansard roof

The upper storey of a building, surrounded by such a roof

a hip roof having two slopes on each side

(of a roof) having two slopes on all sides with the lower slope steeper than the upper