Naysayer (noun)

  1. A person who objects to a proposal or plan and predicts its failure.
  2. A person who denies the validity or feasibility of an idea or suggestion.
  3. A person who takes a negative or critical attitude towards something.

Origin:

Late 19th century: from nay + sayer.

Examples:

  1. The project was opposed by many naysayers who thought it would never succeed.
  2. Despite being a naysayer, he reluctantly agreed to participate in the experiment.
  3. The proposal was met with criticism from the usual naysayers who thought it was too risky.
  4. Her optimism was undaunted by the naysayers who told her she would never make it.
  5. The naysayers were proven wrong when the project turned out to be a huge success.
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