The antonyms for the phrase "fills position" can vary depending on the context in which it is used. Generally, some of the most commonly used antonyms include "vacates position," "quits job," "leaves vacancy," "resigns post," and "abandons responsibility." These terms signify that a person has left an existing position or role and has not been filled by anyone else at that time. These antonyms can be used in situations where a person has retired, relocated, or decided to pursue a different career path, leaving a vacant position behind. Overall, the antonyms for fills position indicate that someone has left their post and there is a need to find a replacement.