from
The Collaborative International Dictionary of English v.0.48
Ptarmigan \Ptar"mi*gan\, n. [Gael. tarmachan; cf. Ir. tarmochan,
tarmonach.] (Zool.)
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.
[1913 Webster]
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 ({Lagopus Scoticus}), is
reddish brown, and does not turn white in winter. The
white, or willow, ptarmigan ({Lagopus albus}) is found
in both Europe and America.
[1913 Webster]