Loon
Loon (lon) , noun
[Scot. loun, lown, loon; akin to OD. loen a stupid man; prob. for an older lown, and akin to English lame.]
A sorry fellow; a worthless person; a rogue.
Loon , noun
[For older loom, Icelandic lōmr; akin to Danish & Swedish lom.]
(Zoology) 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.