\Ptar"mi*gan\, n. [Gael. tarmachan; cf. Ir. tarmochan,
tarmonach.] (Zo["o]l.)
Any grouse of the genus {Lagopus}, of which numerous species
are known. The feet are completely feathered. Most of the
species are brown in summer, but turn white, or nearly white,
in winter.
Note: They chiefly inhabit the northern countries and high
      mountains of Europe, Asia, and America. The common
      European species is {Lagopus mutus}. The Scotch grouse,
      red grouse, or moor fowl ({L. Scoticus}), is reddish
      brown, and does not turn white in winter. The white, or
      willow, ptarmigan ({L. albus}) is found in both Europe
      and America.