Tree swallow Meaning, Definition & Usage

  1. noun bluish-green-and-white North American swallow; nests in tree cavities
    Iridoprocne bicolor; white-bellied swallow.
  2. noun of Australia and Polynesia; nests in tree cavities
    tree martin; Hirundo nigricans.

WordNet

Definitions
  1. (Zoöl.), any one of several species of swallows of the genus Hylochelidon which lay their eggs in holes in dead trees. They inhabit Australia and adjacent regions. Called also martin in Australia.

Webster 1913