Overestimates is the antonym of underestimates. While underestimating something means to underestimate or undervalue its worth, overestimating means the opposite - to overvalue or overrate something. When we overestimate, we tend to see the potential of something to be greater than it actually is, leading to unrealistic expectations. This can often lead to disappointment and frustration. In contrast, underestimating is when we fail to see the full potential of something, leading to missed opportunities or a lack of appreciation. Therefore, it is important to strike a balance when evaluating something, rather than underestimating or overestimating it.