a wild, medium-sized, white goose (Anser caerulescens) with a reddish bill and black wing tips, that breeds in the Arctic and has a bluish-gray color phase if it migrates farther south
See snow goose in American Heritage Dictionary 4
noun
A North American wild goose (Chen caerulescens or Anser caerulescens) that breeds in Arctic regions, having a dusky gray color phase when young and a white plumage with black wingtips as an adult.