Loon (?), n. [Scot. loun, lown, loon; akin to OD. loen a stupid man; prob. for an older lown, and akin to E. lame.]
A sorry fellow; a worthless person; a rogue.
© Webster 1913.
Loon, n. [For older loom, Icel. lmr; akin to Dan. & Sw. lom.] Zool.
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 (U. septentrionalis), are the best known species. See Diver.
© Webster 1913.