Anser anser vs greylag

Anser anser and greylag both are nouns.

Word	Noun	Adjective	Verb	Adverb
Anser anser	Yes	No	No	No
greylag	Yes	No	No	No

As nouns, Anser anser and greylag are synonyms defined as:

Anser anser and greylag: common grey wild goose of Europe; ancestor of many domestic breeds

Other synonyms of Anser anser include graylag, graylag goose, greylag goose.

Anser anser (noun)	greylag (noun)
common grey wild goose of Europe; ancestor of many domestic breeds	common grey wild goose of Europe; ancestor of many domestic breeds