A person who contradicts; someone who denies, opposes, or speaks against something or someone.
From 'contradict' plus the agent suffix '-er' (one who does). 'Contradict' comes from Latin 'contradicere' (contra- opposite + dicere to speak).
Every classroom has a contradicter—that person who challenges everything, and while annoying, they're actually valuable because they force everyone to think harder and defend their ideas.
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