implacable

[im-plak-uh-buhl, -pley-kuh-]

adjective

1. not to be appeased, mollified, or pacified; inexorable.

   an implacable enemy.

   Synonyms: merciless, unbending, unappeasable

implacable

/ ɪmˈplækəbəl /

adjective

1. incapable of being placated or pacified; unappeasable

2. inflexible; intractable

Other Word Forms

• implacability noun
• implacableness noun
• implacably adverb

Word History and Origins

Origin of implacable¹

First recorded in 1375–1425; late Middle English word from Latin word implācābilis. See im- ², placable

Synonym Study

See inflexible.

Example Sentences

The book contains a warning to the BBC from an unnamed source who says William is an "implacable antagonist" and "has people on the case".

Read more on BBC

After taking office, Cheney pursued with implacable vigor his vision of sweeping presidential authority—an idea known as the unitary executive.

Read more on The Wall Street Journal

They call out the industry’s tired shapes, implacable business systems, and unsustainable waste, but in ways that celebrate imagination.

Read more on The Wall Street Journal

For decades, China’s Communist Party has commissioned a steady flow of World War II books, films and television series to bolster its legitimacy, much of which casts Japan as an implacable villain.

Read more on The Wall Street Journal

They – and Netanyahu – have been implacably opposed to any role for the Palestinian Authority in Gaza, and any pathway to a Palestinian State.

Read more on BBC

Related Words

• inexorable 
• intractable 
• relentless 
• ruthless 
• uncompromising 
• unforgiving 
• unrelenting 
• unyielding