Genus Anas refers to the scientific classification of ducks, which belong to the family Anatidae. There are several synonyms for this term, including "wild duck," "waterfowl," and "mallard." These synonyms are commonly used by bird enthusiasts and researchers who study ducks and other waterbirds. The term "wild duck" refers to any duck species that is not domesticated, while "waterfowl" is a broader term encompassing all types of ducks, geese, and swans. Lastly, "mallard" is a popular species of duck that is often used interchangeably with the genus Anas. Regardless of the terminology used, the study and admiration of ducks remains a fascinating and important aspect of ornithology.