a lean-to is a form of:

Lean-to



noun
1.
(a building with a sloping roof resting against the side of a larger building, a temporary shelter of sloping branches, thatch, etc., built by campers, hunters, etc) យ៉ាប (ដំបូលមួយចំហៀង) / បង្ហារគងលើជញ្ជាំង, អាគារមួយទៀត
ENGLISH MEANING
noun
1.
A shed or slight building placed against the wall of a larger structure and having a single-pitched roof; -- called also penthouse, and to-fall.
adjective
1.
Having only one slope or pitch; -- said of a roof.