What is "window martin"

Martin \Mar"tin\, n. [F. martin, from the proper name Martin. Cf. Martlet.] (Zo["o]l.) One of several species of swallows, usually having the tail less deeply forked than the tail of the common swallows. Note: The American purple martin, or bee martin ( Progne subis or Progne purpurea), and the European house martin, or window martin ( Hirundo urbica or Chelidon urbica), are the best known species. Bank martin.

1. The bank swallow. See under Bank.

2. The fairy martin. See under Fairy. Bee martin.

   1. The purple martin.

   2. The kingbird.

      Sand martin, the bank swallow.