1. Bluish-green-and-white North American swallow; nests in tree cavities
   "The tree swallow defended its nest box from competitors";
   - white-bellied swallow, Iridoprocne bicolor
    
2. Of Australia and Polynesia; nests in tree cavities
   "The tree swallow emerged from its nest hole at dawn";
   - tree martin, Hirundo nigricans

Derived forms: tree swallows

Type of: swallow

Part of: genus Hirundo, Hirundo

Encyclopedia: Tree swallow