From Longman Dictionary of Contemporary Englishdundun /dʌn/ noun [uncountable] CCa brownish-grey colour —dun adjective
Examples from the Corpus
dun• The claret dun nymph is at home in slow, peaty streams.• He wore erratically laced army boots, and olive-green fatigues, and a heavy-knit dun brown sweater.• Green, a dull gray or dun.• The rest tended to be solid red or dun, except for the black Døle.• When the dun evening comes the kids go down to the irrigation channels for some bilharzia bathing.• The dun stag stayed back, sidestepping like a boxer.• The attendants were a uniform dun and grey, steel rings of keys at their waists.From Longman Business Dictionarydundun /dʌn/ verb (dunned, dunning) [transitive] American English informal British English old fashioned to demand payment of an unpaid debtThe IRS dunned the corporation for $6.3 million in back tax and penalties.Origin dun Old English dunn