The phrase "puts six feet under" is a colloquial expression meaning to bury someone. Antonyms of this phrase include "resurrects," which is to bring someone back to life from the dead, and "exhumes," which is to dig up someone's body from the grave. Other antonyms could be "saves," which means to rescue someone from death or danger, and "heals," which is to restore someone's health or well-being. In general, antonyms of "puts six feet under" are words or phrases that connote the preservation or restoration of life rather than its end, such as "revives," "rejuvenates," or "restores.