The term "most underlined" implies something that has been marked or emphasized multiple times. Antonyms for this phrase could include "least highlighted," "least emphasized," or "least marked." These words suggest that while the recipient of attention is still noteworthy, it has not received as much focus as something that is "most underlined." These antonyms convey a sense of subtlety, moderation or understatement, and suggest that the recipient of attention may not be as significant as what is "most underlined." When used appropriately, antonyms can add depth and complexity to language and help convey nuanced meaning.