Lemming

n. [Dan. lemming, leming, Nor. lemming, lemīn, Sw. lemel, Lapp. lummīk.] (Zoöl.) A burrowing animal of the rat family and the genus Mus; the M. lemmus, or Norvegicus. These animals are found in the north of Europe, and are remarkable for their periodic migrations in great swarms southward, in which they are said to continue in a straight line, unimpeded by any obstacle, swimming rivers, till they reach the sea, where multitudes are drowned. These migrations occur once in about ten years. [Written also leming.]