perturb

verb

per·​turb pər-ˈtərb 

perturbed; perturbing; perturbs

transitive verb

1

: to cause to be worried or upset : disquiet, unsettle

Half way down the next flight, she smiled to think that a char-woman's stare should so perturb her.

—Edith Wharton

The crowd didn't seem to perturb them in the slightest …

—Nick Hornby

2

: to throw into confusion : disorder

perturbing the social order

3

: to cause to experience a perturbation see perturbation sense 2

Newton finally realized that the planetary orbits would be only approximate ellipses, for the mutual attractions of the planets would perturb their paths.

—Owen Gingerich

perturbable

pər-ˈtər-bə-bəl 

adjective

Did you know?

With its per- prefix, perturb meant originally "thoroughly upset", though today the word has lost most of its intense edge. Perturb and perturbation are often used by scientists, usually when speaking of a change in their data indicating that something has affected some normal process. When someone is referred to as imperturbable, it means he or she manages to remain calm through the most trying experiences.

Synonyms

• agitate
• ail
• alarm
• alarum
• bother
• concern
• derail
• discomfort
• discompose
• dismay
• disquiet
• distemper
• distract
• distress
• disturb
• exercise
• flurry
• frazzle
• freak (out)
• fuss
• hagride
• undo
• unhinge
• unsettle
• upset
• weird out
• worry

Choose the Right Synonym for perturb

discompose, disquiet, disturb, perturb, agitate, upset, fluster mean to destroy capacity for collected thought or decisive action.

discompose implies some degree of loss of self-control or self-confidence especially through emotional stress.

discomposed by the loss of his beloved wife

disquiet suggests loss of sense of security or peace of mind.

the disquieting news of factories closing

disturb implies interference with one's mental processes caused by worry, perplexity, or interruption.

the discrepancy in accounts disturbed me

perturb implies deep disturbance of mind and emotions.

perturbed by her husband's strange behavior

agitate suggests obvious external signs of nervous or emotional excitement.

in his agitated state we could see he was unable to work

upset implies the disturbance of normal or habitual functioning by disappointment, distress, or grief.

the family's constant bickering upsets the youngest child

fluster suggests bewildered agitation.

his declaration of love completely flustered her

Examples of perturb in a Sentence

It perturbed him that his son was thinking about leaving school.

the caller's strange remark perturbed me enough to keep me awake that night

Recent Examples on the Web

Many are pleased by the news, yet simultaneously perturbed by the fact studies linking Red Dye 3 to cancer were released decades ago. —Callum Booth, Forbes, 16 Jan. 2025

Otherwise the plasma will simply stream by, scarcely perturbing our planet. —Meghan Bartels, Scientific American, 30 Dec. 2024

Cutting a long story short, a vocal minority of reactionary gamers is perturbed that a sci-fi video game features a Black samurai protagonist, despite the game’s hokey premise centering on the genetic recording of memories written to computer software. —Lewis Gordon, Vulture, 8 Jan. 2025

Eventually, rescuers located the plane, as well as an unharmed (though understandably perturbed) Jackie. —Scott Travers, Forbes, 5 Jan. 2025

Word History

Etymology

Middle English, from Middle French perturber, from Latin perturbare to throw into confusion, from per- + turbare to disturb — more at turbid

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

perturb

verb

per·​turb pər-ˈtərb 

: to disturb greatly especially in mind

perturbable

-ˈtər-bə-bəl 

adjective