Entry 2 senses · 2 variants Webster, 1913 Underrate /ŭnˌ-dẽrr-āt'/ · Un·der·rate · IPA /ˌʌndərrˈeɪt/ v. t. n. 01 v. t. To rate too low; to rate below the value; to undervalue. 1. To rate too low; to rate below the value; to undervalue. 02 n. A price less than the value; as, to sell a thing at an underrate. 1. A price less than the value; as, to sell a thing at an underrate.