[1] : WordNet (r) 2.0

dud
     adj : failing to detonate; especially not charged with an active
           explosive; "he stepped on a dud mine"
     n 1: someone who is unsuccessful syn: flop, washout
     2: an explosion that fails to occur syn: misfire
     3: an event that fails badly or is totally ineffectual; "the
        first experiment was a real turkey"; "the meeting was a
        dud as far as new business was concerned" syn: turkey,
        bomb
see also:
flop washout misfire turkey bomb 

[2] : Moby Thesaurus II by Grady Ward, 1.0

60 moby thesaurus words for "dud":
   abortion, abortive attempt, also-ran, aspirant, baby kisser,
   bankrupt, blank cartridge, bogy, bomb, bugaboo, bugbear, bust,
   candidate, castrato, cipher, cry of wolf, dark horse,
   defeated candidate, dummy, eunuch, failure, false alarm,
   favorite son, flop, gelding, hollow man, hopeful, impotent,
   incompetent, invalid, jackstraw, lame duck, lay figure, lemon,
   loser, man of straw, merry chase, miscarriage, miscarrying,
   misfire, nebbish, nobody, nonentity, nothing, nullity,
   office seeker, political hopeful, presidential timber, puppet,
   pushover, running mate, stalking-horse, thing of naught, trifle,
   vain attempt, washout, weakling, wet squib, wild-goose chase,
   zero

Dud >> D Words
Dud, definition of term: Dud
dud_pag1.html