The phrase "bringing up the rear" is an idiom that refers to being the last person or thing in a procession or group. Antonyms for this phrase can include terms like "leading the pack," "taking the lead," or "being in the forefront." Other possible antonyms include "at the front," "in the vanguard," or "leading from the front." These terms all suggest that the individual or group in question is at the forefront of a given situation or task, rather than lagging behind. Using these antonyms in place of "bringing up the rear" can help to convey a sense of confidence and assertiveness, and may be especially useful in professional or leadership contexts.