erratic

[ih-rat-ik]

adjective

1. deviating from the usual or proper course in conduct or opinion; eccentric.

   erratic behavior.

   Synonyms: capricious, unstable, unpredictable
   Antonyms: stable, regular, consistent

2. inconsistent, irregular, or unpredictable.

   Many factors affect purchasing power, such as inflation and erratic swings in the stock market.

3. having no certain or definite course or pattern; wandering; not fixed.

   erratic winds.

4. Geology.,  noting or pertaining to a boulder or the like carried by glacial ice and deposited some distance from its place of origin.

5. (of a lichen) having no attachment to the surface on which it grows.

noun

1. an erratic or eccentric person.

2. Geology.,  an erratic boulder or the like.

erratic

/ ɪˈrætɪk /

adjective

1. irregular in performance, behaviour, or attitude; inconsistent and unpredictable

2. having no fixed or regular course; wandering

noun

1. a piece of rock that differs in composition, shape, etc, from the rock surrounding it, having been transported from its place of origin, esp by glacial action

2. an erratic person or thing

Other Word Forms

• erratically adverb
• erraticism noun
• nonerratic adjective
• unerratic adjective

Word History and Origins

Origin of erratic¹

First recorded in 1325–75; Middle English, from Latin errāticus, equivalent to errāt(us) (past participle of errāre “to make a mistake, err” ( err ) + -icus -ic

Word History and Origins

Origin of erratic¹

C14: from Latin errāticus, from errāre to wander, _err

Example Sentences

His behavior was pretty erratic from the first episode out of the pods and that only seemed to continue and worsen.

Read more on Los Angeles Times

Atrial fibrillation is of particular concern because it causes irregular heartbeats and erratic blood flow, raising the risk of blood clots and stroke.

Read more on Science Daily

In the wake of Federline getting full custody, Spears was seen behaving in a way that Federline characterises in his book as erratic.

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They argue that traffic stops — if conducted properly and constitutionally — are also a deterrent for erratic driving.

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A jury convicted Lorincz of manslaughter in August 2024, but the repercussions of her erratic and violent behavior continue to impact the Owens family and their neighbors.

Read more on Los Angeles Times

Related Words

• abnormal 
• arbitrary 
• bizarre 
• capricious 
• eccentric 
• inconsistent 
• irregular 
• mercurial 
• uncertain 
• unreliable 
• unstable 
• unusual 
• volatile 
• wayward 
• weird 
• whimsical