Mer*gan"ser (?), n. [Sp. merg�xa0;nsar, fr. mergo a diver (L. mergus, fr. mergere to dip, dive) + �xa0;nsar goose, L. anser.] Zool.

Any bird of the genus Merganser, and allied genera. They are allied to the ducks, but have a sharply serrated bill.

⇒ The red-breasted merganser (Merganser serrator) inhabits both hemispheres. It is called also sawbill, harle, and sheldrake. The American merganser (M. Americanus.) and the hooded merganser (Lophodytes cucullatus) are well-known species. -- White merganser, the smew or white nun.

© Webster 1913.