merganser

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various fish-eating diving ducks of the genus Mergus or related genera, having a slim hooked bill. Also called sheldrake.

Century Dictionary and Cyclopedia

1. n. A bird of the genus Mergus or subfamily Merginǣ; family Anatidæ; a sawbill, garbill, or fishing-duck. A merganser resembles aduck, but has a cylindrical instead of a depressed bill, with a hooked nail at the end, and a serration of very prominent back-set teeth. Several species are among the common water-fowls of the northern hemisphere. The common merganser or goosander, Mergus merganser or Merganser castor, is about 2 feet long, and nearly 3 in extent of wings. In the male the upper parts are glossy-black varied with white on the wings, the lower parts white tinged with salmon-color, the head and neck glossy dark-green like adrake's, and the bill and feet coral- or vermilion-red. The head is slightly crested. The red-breasted merganser, M. serrator, is a similar but somewhat smaller bird, with a reddish breast and the head more decidedly crested. The hooded merganser, Lophodytes cucullatus, is still smaller, black and white, with a beautiful erect semicircular crest. A South American species, distinct from any of the foregoing, is Mergus branliensis.
2. n. [capitalized] A genus of Merginæ same as Mergus.

Wiktionary

1. n. Any of various diving ducks of the genera Mergus or Lophodytes, which feed on fish and have a sharply serrated bill.

GNU Webster's 1913

1. n. (Zoöl.) Any bird of the genus Mergus (Merganser), and allied genera of the subfamily Merginae. They are allied to the ducks, but have a sharply serrated bill, eat fish, and dive for food. Also called fish duck.

WordNet 3.0

1. n. large crested fish-eating diving duck having a slender hooked bill with serrated edges