The antonyms for the word "over-kills" would be "underwhelms," "undershoots," "fails to impress," or "falls short." Over-kills refer to excessive actions or reactions, especially when they are not necessary, and can be used to describe situations in which someone has gone too far or done too much. Underwhelming, on the other hand, means that someone or something is not impressive or does not meet expectations. Undershooting means that someone has not achieved the desired result, while falls-short means the outcome is not up to standard. Using antonyms for over-kills can help to convey the opposite meaning and bring balance to the conversation or text.