The phrase "live off of" is commonly used to describe relying on something or someone for sustenance. However, there are many other synonyms that can be used for this phrase, such as "depend on," "subsist on," "survive on," "get by on," "exist on," and "sustain oneself with." Each synonym has a slightly different connotation, so it's important to choose the most appropriate term for the situation. Using synonyms can also help to prevent repetition in writing and speech, creating a more dynamic and interesting communication style.