Merganser \Mer*gan"ser\, n. [Sp. merg['a]nsar, fr. mergo a diver (L. mergus, fr. mergere to dip, dive) + ['a]nsar goose, L. anser.]

(Zo["o]l.) Any bird of the genus Merganser, and allied genera. They are allied to the ducks, but have a sharply serrated bill.

Note: 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.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Goosander \Goos"an`der\, n. [OE. gossander, a tautological word formed fr. goose + gander. Cf. Merganser.]

(Zo["o]l.) A species of merganser (M. merganser) of Northern Europe and America; -- called also merganser, dundiver, sawbill, sawneb, shelduck, and sheldrake. See Merganser.

Source: Webster's Revised Unabridged Dictionary (1913)