/ Dictionary / Index I implacable: Meaning and Definition of Find definitions for: im•plac•a•ble Pronunciation: (im-plak'u-bul, -plā'ku-), [key] — adj. not to be appeased, mollified, or pacified; inexorable: an implacable enemy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: implacable (Thesaurus) impish implacental Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language