denouncer

/dɪˈnaʊnsər/
noun
  1. A person who publicly criticizes someone or something, or reports them as being wrong or illegal.
    • The whistleblower became a denouncer of corruption in the company.
    • The newspaper's editor was a vocal denouncer of the new policy.
    • She was known as a fierce denouncer of unfair labor practices.
Antonyms
What does "denouncer" mean? | whatsthatwordmean | whatsthatwordmean