implacable

Definitions

Unable to be placated, appeased, or pacified.

Relentless; unstoppable in one's hostility or purpose.

Examples

The detective remained an implacable foe of the criminal organization, refusing to rest until justice was served.

Despite her repeated apologies, he maintained an implacable expression that suggested he would never forgive her.

The implacable march of time eventually turned the once-thriving city into a collection of ancient ruins.

Synonyms

unappeasable relentless ruthless unforgiving inexorable pitiless inflexible

Antonyms

appeasable forgiving merciful flexible yielding lenient compassionate