killjoy

from WordNet (r) 3.0 (2006)

killjoy
    n 1: someone who spoils the pleasure of others [syn:
         {spoilsport}, {killjoy}, {wet blanket}, {party pooper}]

from The Collaborative International Dictionary of English v.0.48

Kill-joy \Kill"-joy`\, n.
   One who causes gloom or grief; a dispiriting person; a
   spoilsport. --W. Black.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

24 Moby Thesaurus words for "killjoy":
      Cassandra, Eeyore, calamity howler, crepehanger, cynic, damp,
      dampener, damper, defeatist, gloomy Gus, grouch, grump, malcontent,
      malist, negativist, nihilist, pessimist, prophet of doom,
      retreatist, seek-sorrow, sourpuss, spoilsport, wet blanket,
      worrywart

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