perturbation

noun

per·​tur·​ba·​tion ˌpər-tər-ˈbā-shən 

ˌpər-ˌtər-

1

: the action of perturbing : the state of being perturbed

2

: a disturbance of motion, course, arrangement, or state of equilibrium

especially : a disturbance of the regular and usually elliptical course of motion of a celestial body that is produced by some force additional to that which causes its regular motion

perturbational

ˌpər-tər-ˈbā-sh(ə-)nəl 

ˌpər-ˌtər-

adjective

Synonyms of perturbation

• fear
• concern
• anxiety
• worry
• unease
• concernment

Examples of perturbation in a Sentence

a perturbation in the planet's orbit

in her perturbation she kept calling her son, a freshman, to see if everything was all right at college

Recent Examples on the Web

With two satellites at supplementary inclinations, the Newtonian perturbations are equal and opposite in the two orbital planes and cancel each other out. — Jacek Krywko, ArsTechnica, 10 July 2026

First is that quantum transitions must be weak to bring about perturbations in experiments. — Ameya Paleja, Interesting Engineering, 10 July 2026

The presence of a planet causes a tiny perturbation in the lensing of light from the background star. — Robert Lea, Space.com, 24 June 2026

Adopt differential privacy or output perturbation (though this can degrade usefulness). — Lance Eliot, Forbes.com, 1 May 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for perturbation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

perturbation

noun

per·​tur·​ba·​tion ˌpərt-ər-ˈbā-shən 

ˌpər-ˌtər-

1

: the action of perturbing

2

: the state of being perturbed

perturbational

-shnəl 

-shən-ᵊl

adjective