noun, plural lean-tos.
- a shack or shed supported at one side by trees or posts and having an inclined roof.
- a roof of a single pitch with the higher end abutting a wall or larger building.
- a structure with such a roof.
noun plural -tos
- a roof that has a single slope with its upper edge adjoining a wall or building
- a shed or outbuilding with such a roof
n.“building whose rafters pitch against another building or wall,” mid-15c., from lean (v.) + to.