Definitions
1.NounA device or machine that is useless because it does not work properly or has failed to work, such as a bomb, or explosive projectile.
2.NounA failure of any kind.
A loser; an unlucky person.
A lottery ticket that does not give a payout.
3.NounA loser; an unlucky person.
4.NounA lottery ticket that does not give a payout.
5.NounClothes, now always used in plural form duds.
6.Noun↑ Douglas Harper (2001–2026), “dud”, in Online Etymology Dictionary.
7.Noun↑ Transactions of the Philological Society. (1887). United Kingdom: Society, p. 292
8.AdjectiveUseless; failing; ineffective.