Entry 1 sense Webster, 1913 Unforgettable /ŭnˌ-fẽrg-ĕt'-əb-əl/ · Un·for·get·ta·ble · IPA /ˌʌnfə(ɹ)ˈɡɛtəbəl/ 01 a. Not forgettable; enduring in memory. 1. Not forgettable; enduring in memory. “Pungent and unforgettable truths.” — Emerson.