Antonyms for the word "underestimating" are words that convey the opposite meaning. Instead of underestimating, we have words like overestimating, estimating correctly, or overrating. Overestimating suggests that one is assigning more value or importance to something than it actually deserves. Estimating correctly is the opposite of underestimating, as it means to acknowledge the true value or potential of a person, thing, or situation. Overrating is the act of giving something a higher or more significant value than it really deserves, which is the opposite of underestimating. Using these antonyms can help one to convey a more accurate and balanced perspective on things.