Mansard roof : A hipped curb roof; that is, a roof having on all sides two slopes, the lower one being steeper than the upper one.

Example:


Taxonomy
Mansard roof, roof, Mansard, slope, upper slope, free encyclopedia, planes, curb, Weekend song, hip roof, Gambrel roofs, gambrel roof, search, Vampire, Unsourced, Château of Dampierre, Dampierre-en-Yvelines, inner circle.

Defination from the web:
mansard roof was typically used to top a tower element, rather than across the full width of the building. ... a part section through a small timber framed Mansard roof ...