The antonyms for the word "show kindliness" are numerous and varied, depending on the context in which they are used. Some of the most common antonyms include being unkind, being cruel, being mean, being harsh, being self-centered, being unfeeling, and being uncompassionate. Other antonyms may include being unsympathetic, being judgmental, being aggressive, being malevolent, or being ungenerous. All of these words represent a negative and unhelpful approach to others, and they are opposed to the kind and compassionate attitude that the word "show kindliness" embodies. When we use such antonyms, we often reflect our own inner negativity, and we deprive ourselves of the opportunity to connect with others in a positive way.