The antonyms for the word "un-kindness" are numerous, and they all refer to different kinds of positive behaviors. Some of the antonyms could be generosity, kindness, benevolence, compassion, thoughtfulness, helpfulness, hospitality, friendliness, warmth, and cordiality. All these antonyms indicate the opposite of "un-kindness" in different contexts. For instance, generosity is the quality of being liberal in giving, whereas kindness is being friendly, considerate, and sympathetic. Similarly, benevolence pertains to doing good deeds and acts of kindness, and compassion is feeling sympathy for others' suffering. On the other hand, hospitable people are those who welcome guests and treat them with kindness and warmth, while friendly people display a pleasant and sociable attitude.