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The antonym of kind-hearted is cruel or unkind.
To find the antonym of a word, one can start by understanding the meaning of the word itself. "Kind-hearted" implies being compassionate, considerate, and having a sympathetic nature. The antonym, therefore, would be a word that represents the opposite meaning. In this case, the antonym of "kind-hearted" would be "cold-hearted" or "cruel." These words convey a lack of empathy, compassion, and generosity towards others.
