mergansers Definition

any of various fish-eating diving ducks (especially genus Mergus) with a slender bill hooked at the end and serrated along the margins and usually a crested head

a merganser (Mergus merganser) widely distributed in the northern hemisphere with the male having mostly white plumage and a blackish-green head during the breeding season and the female and nonbreeding male having mostly gray plumage and a reddish-brown head —called also goosander