- a roof with a single slope, its upper edge abutting a wall or building
- a shed with a one-slope roof, the upper end of the rafters resting against an external support, such as trees or the wall of a building
- a structure, as the wing of a building, whose roof is a lean-to
- A structure with a single-pitch roof that is attached to the side of a building as a wing or extension.
- A shelter or shed having a roof with a single slope or pitch.
First attested 1461.