also: かわあいさ
noun
common merganser; goosander
A species of duck (Mergus merganser). The name is usually written in katakana as カワアイサ.
カワアイサは川や湖で見られる大型の水鳥です。
The common merganser is a large waterfowl found in rivers and lakes.
The name カワアイサ literally means 'river merganser'. The exact derivation is uncertain, but it likely refers to its habitat.