naysayer

/หˆneษช.หŒseษช.ษš/

IPA: /N EY0 S EY1 ER0/

noun
  1. 1

    One who consistently denies, criticizes, or doubts; a detractor.

    โ€œHe ignored the naysayers and succeeded with his idea.โ€

Source: https://en.wiktionary.org/wiki/naysayer