graylag

[grey-lag] /ˈgreɪˌlæg/
noun
1.
a common, gray, wild goose, Anser anser, of Europe, that is the ancestor of most breeds of domestic goose.
Also, greylag.
Origin
1705-15; gray1 + lag1 (with reference to its habit of remaining longer in England before migrating than other species of the genus)