from
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]