Anseriformes is a taxonomic order that includes approximately 150 species of waterfowl, such as ducks, geese, and swans. These birds are characterized by their short, stout bills, which often have serrated edges or a nail-like structure at the tip, and are adapted for filter-feeding or grazing on aquatic vegetation. Anseriformes species are found worldwide, with the exception of Antarctica, and they inhabit a wide range of wetland habitats, including freshwater lakes, rivers, marshes, and coastal estuaries. Many Anseriformes species are migratory and travel long distances between their breeding and wintering grounds. The order is divided into two families: Anatidae, which includes ducks, geese, and swans, and Anhimidae, which includes screamers, a group of large, terrestrial birds found in South America.

I'm sorry for any confusion, but "geese" is not a medical term. It refers to various waterbirds constituting the family Anatidae and the genus Branta, characterized by a long neck, wide wings, and a honking call. They are not related to human health or medicine. If you have any medical concerns or questions, I'd be happy to help you with those!

"Ducks" is not a medical term. It is a common name used to refer to a group of birds that belong to the family Anatidae, which also includes swans and geese. Some ducks are hunted for their meat, feathers, or down, but they do not have any specific medical relevance. If you have any questions about a specific medical term or concept, I would be happy to help if you could provide more information!

I am not aware of a medical definition for the term "birds." Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, and lightweight but strong skeletons. Some birds, such as pigeons and chickens, have been used in medical research, but the term "birds" itself does not have a specific medical definition.