Simple Definition of implacable
: opposed to someone or something in a very angry or determined way that cannot be changed
Examples of implacable
He 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>
Origin of implacable
Middle English, from Latin implacabilis, from in- + placabilis placable
First Known Use: 15th century
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