imperturbable

1 of 2

adjective

im·​per·​turb·​able ˌim-pər-ˈtər-bə-bəl 

: marked by extreme calm, impassivity, and steadiness : serene

She maintained her imperturbable manner even while being heckled.

imperturbability

ˌim-pər-ˌtər-bə-ˈbi-lə-tē 

noun

imperturbably

ˌim-pər-ˈtər-bə-blē 

adverb

imperturbability

2 of 2

noun

im·​per·​turb·​abil·​i·​ty ˌimpərˌtərbəˈbilətē 

: the quality or state of being imperturbable

no excitement or depression ever disturbed his extraordinary imperturbability

Did you know?

Imperturbable is a bit of a mouthful, but don’t let its five syllables perturb you. Instead, let us break it down: this word, as well as its antonym perturbable, comes from the Latin verb perturbare, meaning "to agitate, trouble, or throw into confusion." Perturbare comes in turn from the combination of per-, meaning "thoroughly," and turbare, meaning "to disturb"; unsurprisingly perturbare is also the source of the English verb perturb. Other perturbare descendants include disturb ("to destroy the tranquility or composure of") and turbid ("thick or opaque with or as if with roiled sediment").

Synonyms of imperturbable

Adjective

• nonchalant
• calm
• serene
• unflappable
• composed
• unshakable
• nerveless

Choose the Right Synonym for imperturbable

cool, composed, collected, unruffled, imperturbable, nonchalant mean free from agitation or excitement.

cool may imply calmness, deliberateness, or dispassionateness.

kept a cool head

composed implies freedom from agitation as a result of self-discipline or a sedate disposition.

the composed pianist gave a flawless concert

collected implies a concentration of mind that eliminates distractions especially in moments of crisis.

the nurse stayed calm and collected

unruffled suggests apparent serenity and poise in the face of setbacks or in the midst of excitement.

harried but unruffled

imperturbable implies coolness or assurance even under severe provocation.

the speaker remained imperturbable despite the heckling

nonchalant stresses an easy coolness of manner or casualness that suggests indifference or unconcern.

a nonchalant driver

Examples of imperturbable in a Sentence

Adjective

Although he seems outwardly imperturbable, he can get very angry at times.

the chef was absolutely imperturbable—even when the kitchen caught on fire

Recent Examples on the Web

Adjective

The imperturbable New York rapper is back behind the boards for a lean, mean new album with endless quotables and only one guest. —Dylan Green, Pitchfork, 28 Jan. 2026

But the Brits love to check an American’s imperturbable optimism. —Rafaela Bassili, Vulture, 3 Dec. 2025

This low-volatility ascent since April quite resembles the imperturbable rally through all of 2017. —Michael Santoli, CNBC, 25 Oct. 2025

Valeska is the movie’s stabilizing presence, imperturbable even in the face of potential natural disaster. —David Rooney, The Hollywood Reporter, 25 Feb. 2025

Word History

Etymology

Adjective

Middle English, from Late Latin imperturbabilis, from Latin in- + perturbare to perturb

First Known Use

Adjective

15th century, in the meaning defined above

Rhymes for imperturbable

• allocable
• educable
• irrigable
• purchasable
• thermostable
• able
• chaebol
• fable
• label
• sable
• stabile
• stable

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Kids Definition

imperturbable

adjective

im·​per·​turb·​able ˌim-pər-ˈtər-bə-bəl 

: hard to disturb or upset

imperturbability

-ˌtər-bə-ˈbil-ət-ē 

noun

imperturbably

-ˈtər-bə-blē 

adverb