<p><strong>Verb</strong></p><ul><li>(used with object) to estimate at too high a value, amount, rate, or the like: Don't overestimate the car's trade-in value.</li><li>to hold in too great esteem or to expect too much from: Don't overestimate him—he's no smarter than you are.</li></ul><p><strong>Noun</strong></p><ul><li>an estimate that is too high.</li></ul>