negater

/nɪˈɡeɪtər/
noun
  1. A person or thing that negates, cancels, or denies something.
    • In the debate, she played the role of the negater, challenging every point.
    • The antidote acts as a negater of the poison's effects.
    • He was known as a negater of new ideas, always finding reasons to reject them.
Antonyms
What does "negater" mean? | whatsthatwordmean | whatsthatwordmean