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)
 

Sheldrake \Shel"drake`\, n. [Sheld + drake.]

1. (Zo["o]l.) Any one of several species of large Old World ducks of the genus Tadorna and allied genera, especially the European and Asiatic species. (T. cornuta, or tadorna), which somewhat resembles a goose in form and habit, but breeds in burrows.

Note: It has the head and neck greenish black, the breast, sides, and forward part of the back brown, the shoulders and middle of belly black, the speculum green, and the bill and frontal bright red. Called also shelduck, shellduck, sheldfowl, skeelduck, bergander, burrow duck, and links goose.

Note: The Australian sheldrake (Tadorna radja) has the head, neck, breast, flanks, and wing coverts white, the upper part of the back and a band on the breast deep chestnut, and the back and tail black. The chestnut sheldrake of Australia (Casarca tadornoides) is varied with black and chestnut, and has a dark green head and neck. The ruddy sheldrake, or Braminy duck (C. rutila), and the white-winged sheldrake (C. leucoptera), are related Asiatic species.

2. Any one of the American mergansers.

Note: The name is also loosely applied to other ducks, as the canvasback, and the shoveler.

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)