Entry 1 sense Webster, 1913 Undervaluation /ŭn'-dẽrv-ălˌ-yo͞o-āsh'-ən/ · Un·der·val·u·a·tion · IPA /ˈʌndərvˌæljuːˈeɪʃən/ 01 n. The act of undervaluing; a rate or value not equal to the real worth. 1. The act of undervaluing; a rate or value not equal to the real worth.