From Longman Dictionary of Contemporary EnglishRelated topics: Coloursdundun /dʌn/ noun [uncountable]CCa brownish-grey colour —dun adjectiveExamples from the Corpusdun• The claretdunnymph is at home in slow, peaty streams.• He wore erratically lacedarmyboots, and olive-green fatigues, and a heavy-knit dun brown sweater.• Green, a dullgray 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 dunstag stayed back, sidestepping like a boxer.• The attendants were a uniformdun and grey, steel rings of keys at their waists.From Longman Business Dictionarydundun /dʌn/ verb (dunned, dunning) [transitive] American English informal British English old fashionedto demand payment of an unpaid debtThe IRS dunned the corporation for 6ドル.3 million in back tax and penalties.OrigindunOld Englishdunn