Entry 2 senses Webster, 1913 Implacable /ĭmˌ-plăk'-əb-əl/ · Im·pla·ca·ble · IPA /ɪmˈplækəbəl/ 01 a. Not placable; not to be appeased; incapable of being pacified; inexorable; as, an implacable prince. 1. Not placable; not to be appeased; incapable of being pacified; inexorable; as, an implacable prince. “I see thou art implacable.” — Milton. “An object of implacable enmity.” — Macaulay. 2. Incapable of being relieved or assuaged; inextinguishable.[R.] “O! how I burn with implacable fire.” — Spenser. “Which wrought them pain Implacable, and many a dolorous groan.” — Milton. Syn. Unappeasable; inexorable; irreconcilable; unrelenting; relentless; unyielding.