adjective im·per·turb·able \ ˌim-pər-ˈtər-bə-bəl \
Updated on: 29 Mar 2018

Definition of imperturbable

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


play \ˌim-pər-ˌtər-bə-ˈbi-lə-tē\ noun


play \ˌim-pər-ˈtər-bə-blē\ adverb

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Examples of imperturbable in a Sentence

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

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

Recent Examples of imperturbable from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'imperturbable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

There is an interesting time lag between the appearance of "imperturbable" and its antonym, "perturbable." Although "imperturbable" is known to have existed since the middle of the 15th century, "perturbable" didn't show up in written English until 1800. The verb "perturb" (meaning "to disquiet" or "to throw into confusion") predates both "imperturbable" and "perturbable"; it has been part of English since the 14th century. All three words derive from Latin perturbare (also meaning "to throw into confusion"), which in turn comes from the combination of per- and turbare, which means "to disturb." Other relatives of "imperturbable" include "disturb" and "turbid."

Origin and Etymology of imperturbable

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

Synonym Discussion of 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

IMPERTURBABLE Defined for English Language Learners


Definition of imperturbable for English Language Learners

  • : very calm : very hard to disturb or upset

IMPERTURBABLE Defined for Kids


adjective im·per·turb·able \ ˌim-pər-ˈtər-bə-bəl \

Definition of imperturbable for Students

: hard to disturb or upset : very calm
  • an imperturbable teacher

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