From Longman Dictionary of Contemporary Englishduddud /dʌd/ noun [countable] 1 USELESSsomething that is useless, especially because it does not work correctly Several of the fireworks were duds.2 → duds —dud adjective a dud light bulb
Examples from the Corpus
dud• Critics have labeled the new telescope a dud.• I've learnt about 60 I suppose overall and half of them are duds naughty words or words for something completely different.• Pauley's last performance was a major dud.• There were no duds among the three 1992 Piedmont wines I tried.• There are a couple of duds on Double Good Everything but there's also a sharper sense of purpose.• Even with the advantages of other income sources, studios depend on a few hits to pay for a large number of duds.From Longman Business Dictionaryduddud /dʌd/ noun [countable] informal something that is useless or of bad quality, especially because it does not work correctlyThe new system turned out to be a market dud. —dud adjectivedud results from biotech companies 