Implacable is rooted in Latin placare, meaning "to soothe," but its im- prefix is a variant of the negating prefix in- (as in inactive) and it signals that there’s nothing warm and fuzzy here. Someone or something described as implacable cannot be soothed, which usually means trouble: implacable is most often attached to words like foe, enemy, hatred and hostility. The opposite of implacable is, of course, placable; it means "easily soothed," but sadly isn’t called upon very often. Another placare word is likely more familiar. Placate means "to soothe or appease"; it’s frequently applied when an angry person is made to feel less so.
Examples of implacable in a SentenceHe has an implacable hatred for his political opponents. an implacable judge who knew in his bones that the cover-up extended to the highest levels of government
Recent Examples on the Web Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback. Blue metal boxes on posts line the roadway, a slot beckoning a few coins to the Imam Khomeini Relief Foundation, named for the cleric who, in 1979, turned Iran from Israel’s stalwart ally to its implacable foe. —Karl Vick, Time, 13 June 2025 The compulsion of doctors to write, then, may simply be an extension of the reason so many of us entered medicine—an implacable curiosity about how people tick. —Danielle Ofri, New Yorker, 7 June 2025 The scenes of poor Pabst trying to help her while suffering the glare of her implacable egocentricity are perhaps the funniest—and, in some ways, the saddest—in the novel. —David Denby, New Yorker, 23 May 2025 So many of these shows focus on the futility or grim determination or flawed goofiness of a few individuals set against the massive implacable nightmare of giant institutions. —Kathryn Vanarendonk, Vulture, 17 May 2025 See All Example Sentences for implacable Word HistoryEtymology
Middle English, from Latin implacabilis, from in- + placabilis placable
First Known Use
15th century, in the meaning defined above
Time Traveler
The first known use of implacable was in the 15th century Cite this Entry“Implacable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/implacable. Accessed 8 Jul. 2025.
Last Updated: 7 Jul 2025 - Updated example sentencesLove words? Need even more definitions?
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