Antonyms for the word "under-average" refer to terms that describe something that exceeds or goes beyond the norm. Some of the antonyms for this term may include words such as "excellent," "exceptional," "superior," "outstanding," and "above-average." These words denote a higher level of achievement, performance, or quality. They highlight that something is beyond the standardized or known level of proficiency, success, or accomplishment. Some other antonyms for "under-average" could be "extraordinary," "remarkable," "impressive," and "first-rate." Using these antonyms in place of "under-average" can help to better convey a sense of excellence or brilliance.