Webster's 1913 Dictionary
STIFFTAIL
STIFFTAIL Stiff "tail `, n.
Defn: The ruddy duck. [Local, U.S.]
New American Oxford Dictionary
stifftail
stiff tail |ˈstifˌtāl ˈstɪfteɪl |(also stiff-tailed duck ) ▶noun a diving duck with a stiff tail of pointed feathers, often held up at an angle. [Family Anatidae: four genera, in particular Oxyura, and several species, e.g., the ruddy duck. ]
Oxford Dictionary
stifftail
stifftail (also stiff-tailed duck ) ▶noun a diving duck with a stiff tail of pointed feathers, often held up at an angle. ●Family Anatidae: four genera, in particular Oxyura, and several species, e.g. the ruddy duck.
The Wordsmith Dictionary