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 (Zoöl.), the hooded crow; -- so called from its color; -- also called hoody, and hoddy. -- Dun diver (Zoöl.), the goosander or merganser.
Dun"bird` (?), n. [Named from its color.] (Zoöl.) (a) The pochard; -- called also dunair, and dunker, or dun- curre. (b) An American duck; the ruddy duck.
Dunce (?), n. [From Joannes Duns Scotus, a schoolman called the Subtle Doctor, who died in 1308. Originally in the phrase "a Duns man". See Note below.] One backward in book learning; a child or other person dull or weak in intellect; a dullard; a dolt.