perturbation

When you're on an airplane with your friend who's terrified of flying, you'll be able to sense her perturbation, even if she doesn't say a word about how scared she is. The noun perturbation means "anxiety or uneasiness".

Perturbation means "a state of agitation," or it can refer to whatever's causing the anxiety. Your brother's weird haircut could be the perturbation that's upsetting your mom at Thanksgiving dinner. It usually means a personal feeling of upset or nervousness, but perturbation can also be a physical disruption of some kind, like a perturbation in a river that makes the water become choppy and dangerous. In astronomy, perturbation is a change caused by the gravitational pull of a celestial body.

Primary Meanings of perturbation

1.
n
the act of causing disorder
2.
n
(physics) a secondary influence on a system that causes it to deviate slightly
Full Definitions of perturbation
1

n the act of causing disorder

Synonyms:
disruption
Types:
breakdown, dislocation
the act of disrupting an established order so it fails to continue
surprisal, surprise
the act of surprising someone
Type of:
disturbance
the act of disturbing something or someone; setting something in motion

n an unhappy and worried mental state

Synonyms:
disturbance, upset
Type of:
agitation
a mental state of extreme emotional disturbance

n a disposition that is confused or nervous and upset

Synonyms:
fluster
Type of:
discomposure
a temperament that is perturbed and lacking in composure

n activity that is a malfunction, intrusion, or interruption

“the term `distress' connotes some degree of perturbation and emotional upset”
Synonyms:
disturbance
Types:
bother, fuss, hassle, trouble
an angry disturbance
magnetic storm
a sudden disturbance of the earth's magnetic field; caused by emission of particles from the sun
Type of:
activity
any specific behavior
2

n (physics) a secondary influence on a system that causes it to deviate slightly

Types:
variation
(astronomy) any perturbation of the mean motion or orbit of a planet or satellite (especially a perturbation of the earth's moon)
libration
(astronomy) a real or apparent slow oscillation of a moon or satellite
Type of:
influence
the effect of one thing (or person) on another

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