The antonyms for the word "under-estimated" are "over-estimated," "overrated," and "exaggerated." When someone is over-estimated or overrated, they are regarded as better or more important than they actually are. This often leads to unrealistic expectations and disappointment when they fail to live up to the hype. Exaggeration, on the other hand, involves making something seem more significant, impressive, or powerful than it really is. When people exaggerate, they may distort the truth to make something appear better or worse than it is. Therefore, it is essential to avoid underestimating or over-estimating people, events, or situations and try to maintain a balanced perspective.