"Fart around" is an informal expression that means to waste time or procrastinate. There are many synonyms for this phrase, including dawdle, loiter, goof off, procrastinate, lollygag, and dilly-dally. Other similar phrases include "drag one's feet," "putter around," "muck about," "idle away," and "kill time." While these expressions are casual and somewhat humorous, they can also convey a lack of productivity or a lack of seriousness about a given task. Rather than "farting around," it's always better to stay focused and maximize your time to achieve your goals in an efficient manner.