Un-kinder is an adjective that means lacking kindness or being unkind. Antonyms are words that have opposite meanings to each other. Therefore, antonyms for "un-kinder" would include any word that signifies kindness, benevolence, or compassion. Some possible antonyms for un-kinder include words like kind, nice, friendly, compassionate, caring, humane, thoughtful, gentle, considerate, polite, generous, loving, and sympathetic. Using antonyms for un-kinder can help convey a positive message, highlighting the importance of being compassionate and empathetic towards others. Choosing to use antonyms that promote kindness can also help foster healthy relationships and build a more positive community.