A gambrel or gambrel roof is a usually symmetrical two-sided roof with two slopes on each side. The upper slope is positioned at a shallow angle, while the lower slope is steep. This design provides the advantages of a sloped roof while maximizing headroom inside the building's upper level and shortening what would otherwise be a tall roof, as well as reducing the span of each set of rafters. The name comes from the Medieval Latin word gamba, meaning horse's hock or leg. The term gambrel is of American origin, the older, European name being a curb (kerb, kirb) roof.
Europeans historically did not distinguish between a gambrel roof and a mansard roof but called both types a mansard. In the United States, various shapes of gambrel roofs are sometimes called Dutch gambrel or Dutch Colonial gambrel with bell-cast eaves, Swedish, German, English, French, or New England gambrel.