pessimist       
noun [ C ] uk/ˈpes.ɪ.mɪst/ us/ˈpes.ə.mɪst/
 悲观主义者
a person who thinks that bad things are more likely to happen or who emphasizes the bad part of a situation
  Don't be such a pessimist! 不要这么悲观! 
 Change may not come as fast, or as brutally, as the pessimists fear. 变化可能不会像悲观主义者所担心的那样快,或那样残酷地到来。 
 See: pessimism
 - More examples
 - Pessimists point out that every attempt to change the council's composition has failed.
 - Britain's deficit was a lot worse than the City's gloomiest pessimists had expected.
 - The only difference between an optimist and a pessimist is what they chose to focus on.