\Tun"dra\, n. [Russ.]
One of the level or undulating treeless plains characteristic
of northern arctic regions in both hemispheres. The tundras
mark the limit of arborescent vegetation; they consist of
black mucky soil with a permanently frozen subsoil, but
support a dense growth of mosses and lichens, and dwarf herbs
and shrubs, often showy-flowered.

\Tun"dra\, n. [Russ., from a native name.]
A rolling, marshy, mossy plain of Northern Siberia.