From WordNet (r) 3.0 (2006):
dun
adj 1: of a dull greyish brown to brownish grey color; "the dun
and dreary prairie"
n 1: horse of a dull brownish grey color
2: a color or pigment varying around a light grey-brown color;
"she wore dun" [syn: dun, greyish brown, grayish brown,
fawn]
v 1: treat cruelly; "The children tormented the stuttering
teacher" [syn: torment, rag, bedevil, crucify,
dun, frustrate]
2: persistently ask for overdue payment; "The grocer dunned his
customers every day by telephone"
3: cure by salting; "dun codfish"
4: make a dun color