implacable
adjective
im·pla·ca·ble (ˌ)im-ˈpla-kə-bəl 
-ˈplā-
-ˈplā- : not placable : not capable of being appeased, significantly changed, or mitigated
an implacable enemy
implacability
(ˌ)im-ˌpla-kə-ˈbi-lə-tē
noun -ˌplā-
implacably
(ˌ)im-ˈpla-kə-blē
adverb -ˈplā-
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How Should You Use implacable?
Implacable is based on the Latin verb placare, meaning "to calm" or "to soothe." It joins the negative im- to the root to describe something that cannot be calmed or soothed or altered. The root placare also gave us placate. You may ask, what about the similar-looking words placid and placebo? These words are related to implacable and placate, but not as closely as you might suspect. They come from the Latin verb placēre, a relative of placare that means "to please."
Synonyms
- adamant
- adamantine
- bullheaded
- dogged
- hard
- hard-nosed
- hardened
- hardheaded
- headstrong
- immovable
- inconvincible
- inflexible
- intransigent
- mulish
- obdurate
- obstinate
- opinionated
- ossified
- pat
- pertinacious
- perverse
- pigheaded
- self-opinionated
- self-willed
- stiff-necked
- stubborn
- unbending
- uncompromising
- unrelenting
- unyielding
- willful
- wilful
See all Synonyms & Antonyms 
Example Sentences
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
Recent Examples on the Web These women found Highsmith’s gamine attractiveness as irresistible as the camera does and her implacable character no less so. 
Mark Feeney, BostonGlobe.com, 7 Sep. 2022 Friday’s attack was a reminder of just how implacable those enemies are, and a reminder, at a timely moment, that, when an autocrat encourages violence, violence happens. Adam Gopnik, The New Yorker, 13 Aug. 2022 And above all of it, those two implacable signs: #YouNext. Laura Jedeed, The New Republic, 9 Aug. 2022 The United States and China had been implacable foes for decades. Michael Schuman, The Atlantic, 11 Aug. 2022 But Kelly Reilly as the implacable Beth Dutton remains an acting tour de force, in particular for her biting line delivery that only gets more delicious (and absurd) as the episodes roll by. Lauren Puckett-pope, ELLE, 13 July 2022 With the implacable refusal of the G.O.P. on Capitol Hill to approve meaningful gun-control measures, the President is setting a very low bar. John Cassidy, The New Yorker, 13 June 2022 Here, the sight of the Landlords with their implacable stance and extravagant costumes creates a terrifying world — somehow one even more eerie than when the wilis take over the stage in Act 2. New York Times, 9 June 2022 All of these last four films follow in the path of Cimino’s first three as outpourings of loss and grief in the face of implacable power. Richard Brody, The New Yorker, 22 May 2022 See More
Mark Feeney, BostonGlobe.com, 7 Sep. 2022 Friday’s attack was a reminder of just how implacable those enemies are, and a reminder, at a timely moment, that, when an autocrat encourages violence, violence happens. Adam Gopnik, The New Yorker, 13 Aug. 2022 And above all of it, those two implacable signs: #YouNext. Laura Jedeed, The New Republic, 9 Aug. 2022 The United States and China had been implacable foes for decades. Michael Schuman, The Atlantic, 11 Aug. 2022 But Kelly Reilly as the implacable Beth Dutton remains an acting tour de force, in particular for her biting line delivery that only gets more delicious (and absurd) as the episodes roll by. Lauren Puckett-pope, ELLE, 13 July 2022 With the implacable refusal of the G.O.P. on Capitol Hill to approve meaningful gun-control measures, the President is setting a very low bar. John Cassidy, The New Yorker, 13 June 2022 Here, the sight of the Landlords with their implacable stance and extravagant costumes creates a terrifying world — somehow one even more eerie than when the wilis take over the stage in Act 2. New York Times, 9 June 2022 All of these last four films follow in the path of Cimino’s first three as outpourings of loss and grief in the face of implacable power. Richard Brody, The New Yorker, 22 May 2022 See More Word History
Etymology
Middle English, from Latin implacabilis, from in- + placabilis placable
First Known Use
15th century, in the meaning defined above
Kids Definition
implacable
adjective
im·pla·ca·ble im-ˈpla-kə-bəl
-ˈplā-
: impossible to please, satisfy, or change
implacable enemies
implacable
adjective
1
as in stubborn
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
Relevance
- stubborn
- adamant
- steadfast
- unyielding
- obstinate
- obdurate
- unrelenting
- unbending
- hardened
- intransigent
- uncompromising
- wilful
- immovable
- pertinacious
- adamantine
- obsessive
- mulish
- inflexible
- willful
- dogged
- headstrong
- relentless
- persistent
- hardheaded
- opinionated
- hard
- pigheaded
- perverse
- bullheaded
- ossified
- inexorable
- determined
- hard-nosed
- strict
- pat
- self-willed
- unflinching
- stiff-necked
- inconvincible
- tenacious
- stern
- rigid
- self-opinionated
- defiant
- iron
- severe
- wayward
- indomitable
- unconquerable
- wrongheaded
- deaf to reason
- resolved
- single-minded
- intractable
- cantankerous
- contumacious
- bloody-minded
- uncooperative
- mutinous
- recalcitrant
- hidebound
- invincible
- unmanageable
- ungovernable
- firm
- contrary
- inveterate
- unruly
- disobedient
- hell-bent
- stouthearted
- exacting
- hard-line
- refractory
- anal-retentive
- insubordinate
- hard-shelled
- insurgent
- demanding
- narrow-minded
- froward
- cussed
- confirmed
- set
- unregenerate
- hard-shell
Antonyms & Near Antonyms
- acquiescent
- agreeable
- pliant
- amenable
- flexible
- pliable
- docile
- complying
- compliant
- obedient
- tractable
- submissive
- placable
- yielding
- responsive
- receptive
- relenting
- reasonable
- willing
- accepting
- temperate
- slavish
- subservient
- persuadable
- manageable
- 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
- unyielding
- unrelenting
- ruthless
- unflinching
- unappeasable
- stubborn
- dogged
- merciless
- tenacious
- obdurate
- willful
- pertinacious
- hard
- intractable
- persevering
- mulish
- pigheaded
- unforgiving
- peevish
- uncooperative
- hardheaded
- headstrong
- opinionated
- perverse
- wilful
- self-willed
Antonyms & Near Antonyms
- softening
- impotent
- weak
- yielding
- slackening
- complaisant
- spineless
- slack
- pliant
- pliable
- invertebrate
- obliging