| any of several North American birds of the genus Hirundo, esp. H. pyrrhonota, that live colonially and build bottle-shaped mud nests on cliffs and walls. |
| cliff swallow n. A North American swallow (Petrochelidon pyrrhonota) that builds a bottle-shaped nest of mud, grass, and twigs on the face of a cliff or bluff or under the eaves of a roof. |