Synonyms of implacable

implacable

adjective

(ˌ)im-ˈpla-kə-bəl 

1

as in adamant

sticking to an opinion, purpose, or course of action in spite of reason, arguments, or persuasion

an implacable judge who knew in his bones that the cover-up extended to the highest levels of government

Synonyms & Similar Words

• adamant
• stubborn
• steadfast
• obstinate
• hardened
• unrelenting
• unyielding
• obdurate
• unbending
• intransigent
• uncompromising
• immovable
• adamantine
• pertinacious
• mulish
• inflexible
• obsessive
• willful
• bullheaded
• dogged
• headstrong
• opinionated
• hardheaded
• perverse
• hard
• persistent
• ossified
• relentless
• pigheaded
• pat
• hard-nosed
• determined
• strict
• inexorable
• self-willed
• stiff-necked
• unflinching
• inconvincible
• tenacious
• stern
• iron
• self-opinionated
• deaf to reason
• rigid
• defiant
• severe
• resolved
• wayward
• wrongheaded
• hard-line
• single-minded
• indomitable
• cantankerous
• unconquerable
• intractable
• stouthearted
• contumacious
• uncooperative
• hidebound
• recalcitrant
• mutinous
• invincible
• narrow-minded
• unmanageable
• bloody-minded
• contrary
• firm
• ungovernable
• disobedient
• unruly
• anal-retentive
• inveterate
• hard-shell
• refractory
• hell-bent
• insubordinate
• exacting
• insurgent
• cussed
• set
• demanding
• confirmed
• froward
• unregenerate

Antonyms & Near Antonyms

• flexible
• agreeable
• acquiescent
• amenable
• complying
• pliant
• compliant
• pliable
• docile
• obedient
• yielding
• tractable
• submissive
• responsive
• willing
• receptive
• accepting
• reasonable
• placable
• relenting
• manageable
• temperate
• slavish
• subservient
• persuadable
• governable

2

as in relentless

showing no signs of slackening or yielding in one's purpose

an implacable dedication to the proposition that everyone is entitled to a quality education

Synonyms & Similar Words

• relentless
• grim
• determined
• persistent
• unrelenting
• ruthless
• unyielding
• unflinching
• unappeasable
• dogged
• stubborn
• willful
• merciless
• tenacious
• hard
• obdurate
• intractable
• pertinacious
• uncooperative
• mulish
• peevish
• opinionated
• headstrong
• unforgiving
• hardheaded
• perverse
• persevering
• pigheaded
• self-willed

Antonyms & Near Antonyms

• softening
• yielding
• weak
• impotent
• slack
• spineless
• slackening
• invertebrate
• complaisant
• pliable
• pliant
• obliging

Example Sentences

Recent Examples of implacable

But bonding keeps getting interrupted as big, implacable questions rear their head, like wildebeests slowly amassing and waiting to stampede. — Sara Holdren, Vulture, 20 May 2026

As this Premier League campaign has perhaps demonstrated more than most others, Villa do not need to be implacable to achieve their objectives. — Jacob Tanswell, New York Times, 26 Apr. 2026

But absent an oil-rich ally, like Russia or Venezuela, and faced with an implacable enemy, Cuban officials may have no choice but to bring Cuba back into the orbit of American power, at least for now. — Joseph J. Gonzalez, The Conversation, 23 Mar. 2026

But as all the world knows, Edmond Dantès did rise again, transformed from an innocent young sailor into that courtly yet implacable avenger, the Count of Monte Cristo. — Michael Dirda, The New York Review of Books, 19 Mar. 2026

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