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

: very calm : very hard to disturb or upset

Full Definition of IMPERTURBABLE

:  marked by extreme calm, impassivity, and steadiness :  serene
im·per·turb·abil·i·ty \-ˌtər-bə-ˈbi-lə-tē\ noun
im·per·turb·ably \-ˈtər-bə-blē\ adverb


  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>


Middle English, from Late Latin imperturbabilis, from Latin in- + perturbare to perturb
First Known Use: 15th century

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 Kids


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

Definition of IMPERTURBABLE for Kids

:  hard to disturb or upset :  very calm <an imperturbable teacher>


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