The antonyms for the word "overestimates" are "underestimates" or "undervalues". These words indicate a situation where someone judges the value, ability, or importance of something as being lower than it really is. Underestimating can lead to missed opportunities or undervaluing, which can result in a lack of recognition or appreciation. Therefore, it is essential to be mindful and avoid underestimating people, things, or situations, and instead, give them the credit and recognition that they deserve. This will help cultivate a culture of respect, fairness, and openness in our personal and professional lives.