[dun] adj [ME, fr. OE dunn--more at dusk] (bef. 12c) 1 a: having the color dun b of a horse: having a grayish yellow coat with black mane and tail
2: marked by dullness and drabness -- dun.ness n
[2]dun n (14c) 1: a dun horse
2: a variable color averaging a nearly neutral slightly brownish dark gray
3: a subadult mayfly; also: an artificial fly tied to imitate such an insect [3]dun vt dunned ; dun.ning [origin unknown] (ca. 1626) 1: to make persistent demands upon for payment
2: plague, pester [4]dun n (1628) 1: one who duns
2: an urgent request; esp: a demand for payment