To portray or describe someone or something as evil or demonic; to vilify or condemn severely.
From demon + -ise (British spelling of -ize). The verb form creates the action of describing something as demonic or evil.
Political rhetoric constantly demonises opponents—calling them 'evil' or 'demonic'—which research shows actually makes people less likely to listen to opposing views because once you've demonised someone, dialogue seems impossible.
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