wild-goose

An aquatic fowl of the genus Anas, the Anas anser, a fowl of passage. These geese fly to the south in autumn, and return to the north in the spring. This species is the stock of the common domestic goose. The wild goose of North America, also migratory, is a distinct species, the Anas canadensis. Wild-goose chase, the pursuit of something as unlikely to be caught as the wild goose.