The Collaborative International Dictionary
Colymbus torquatus
Loon \Loon\, n. [For older loom, Icel. l[=o]mr; akin to Dan. & Sw. lom.] (Zo["o]l.) Any one of several aquatic, wed-footed, northern birds of the genus Urinator (formerly Colymbus), noted for their expertness in diving and swimming under water. The common loon, or great northern diver ( Urinator imber, or Colymbus torquatus), and the red-throated loon or diver ( Urinator septentrionalis), are the best known species. See Diver.