Wordnet 3.0
NOUN (1)
1.
any of various short-tailed furry-footed rodents of circumpolar distribution;
The Collaborative International Dictionary of English v.0.48:
Lemming \Lem"ming\ (l[e^]m"m[i^]ng), n. [Nor. lemming, lemende;
cf. Sw. lemel, Lapp. lummik.] (Zool.)
Any one of several species of small arctic rodents of the
genera Myodes and Cuniculus, resembling the meadow mice
in form. They are found in both hemispheres.
[1913 Webster]
Note: The common Northern European lemming (Myodes lemmus)
is remarkable for making occasional devastating
migrations in enormous numbers from the mountains into
the lowlands.
[1913 Webster]
WordNet (r) 3.0 (2006):
lemming
n 1: any of various short-tailed furry-footed rodents of
circumpolar distribution