The phrase "sleep off" typically refers to the act of recovering from a hangover or illness by getting some rest. Some synonyms for this phrase include "nap away," "snooze it off," "doze it out," and "slumber it off." Other similar phrases might include "catch some Z's," "get some shut-eye," or "recharge through sleep." Each of these phrases implies a period of rest and sleep that is intended to help someone recover or restore their energy levels. While they may vary in their connotation or specific usage, each of these phrases conveys the idea of using sleep as a way to feel better and reinvigorate one's body and mind.