The Collaborative International Dictionary
Dun diver
Dun \Dun\, a. [AS. dunn, of Celtic origin; cf. W. dwn, Ir. & Gael. donn.] Of a dark color; of a color partaking of a brown and black; of a dull brown color; swarthy.
Summer's dun cloud comes thundering up. -- Pierpont.
Chill and dun
Falls on the moor the brief November day.
--Keble.
Dun crow (Zo["o]l.), the hooded crow; -- so called from its color; -- also called hoody, and hoddy.
Dun diver (Zo["o]l.), the goosander or merganser.
Wiktionary
dun diver
n. The goosander or merganser.