definition of a lemming
lemming. n. 1. (Animals) any of various volelike rodents of the genus Lemmus and related genera, of northern and arctic regions of Europe, Asia, and North America: family Cricetidae.emming. n. 1. (Animals) any of various volelike rodents of the genus Lemmus and related genera, of northern and arctic regions of Europe, Asia, and North America: family Cricetidae.