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

"Dun codfish."

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."