Definition of "Dun" :
noun: horse of a dull brownish grey color
noun: a color or pigment varying around a light grey-brown color
"She wore dun."
verb: make a dun color
verb: cure by salting
verb: persistently ask for overdue payment
"The grocer dunned his customers every day by telephone."
verb: treat cruelly
adjective: of a dull greyish brown to brownish grey color
"The dun and dreary prairie."