ptar·mi·gan / ˈtärməgən/ • n. (pl. same or ptarmigans ) a northern grouse, esp. the rock ptarmigan (Lagopus mutus) of Eurasia and North America, with feathered legs and feet and plumage that typically changes to white in winter.

ptarmigan Any of three species of northern or alpine grouse, all of which have feathered legs; especially the Eurasian ptarmigan, Lagopus mutus. The wings and breast are white in colder months, but in the spring they become a mottled grey-brown. It inhabits high barren regions, feeding on leaves and lichens. Length: to 36cm (14in). Family Tetraonidae.

ptarmigan XVI. Early forms (in Sc. use) termigan(t), termagant, tormichan — Gael. tarmachan, of unkn. orig.; fancifully sp. ptarmigan (XVII) after Gr. words with pt-, e.g. pterón wing.