The phrase "most physic" refers to the medicine or treatment that is most effective for a particular ailment. There are several synonyms that can be used in place of this phrase. One such synonym is "most potent," which refers to the medicine or treatment that is most powerful or effective. Another synonym is "most efficacious," which means that the treatment is the most likely to produce the desired results. "Most curative" is another synonym that can be used, which indicates that the treatment has the potential to cure the ailment. Other synonyms for "most physic" include "most therapeutic," "most remedial," and "most healing".