er·​rat·​ic | \i-ˈra-tik \

Definition of erratic 

(Entry 1 of 2)

1 : having no fixed course : wandering an erratic comet

2a : characterized by lack of consistency, regularity, or uniformity erratic dieting keeps erratic hours

b : deviating from what is ordinary or standard : eccentric an erratic genius

3 : transported from an original resting place especially by a glacier an erratic boulder

4 archaic : nomadic



Definition of erratic (Entry 2 of 2)

: one that is erratic (see erratic entry 1) especially : a boulder or block of rock transported from its original resting place especially by a glacier

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Other Words from erratic


erratical \i-​ˈra-​ti-​kəl \ adjective
erratically \i-​ˈra-​ti-​k(ə-​)lē \ adverb
erraticism \i-​ˈra-​tə-​ˌsi-​zəm \ noun

Choose the Right Synonym for erratic


strange, singular, unique, peculiar, eccentric, erratic, odd, quaint, outlandish mean departing from what is ordinary, usual, or to be expected. strange stresses unfamiliarity and may apply to the foreign, the unnatural, the unaccountable. a journey filled with strange sights singular suggests individuality or puzzling strangeness. a singular feeling of impending disaster unique implies singularity and the fact of being without a known parallel. a career unique in the annals of science peculiar implies a marked distinctiveness. the peculiar status of America's first lady eccentric suggests a wide divergence from the usual or normal especially in behavior. the eccentric eating habits of preschoolers erratic stresses a capricious and unpredictable wandering or deviating. a friend's suddenly erratic behavior odd applies to a departure from the regular or expected. an odd sense of humor quaint suggests an old-fashioned but pleasant oddness. a quaint fishing village outlandish applies to what is uncouth, bizarre, or barbaric. outlandish fashions of the time

Did You Know?

Erratic can refer to literal "wandering". A missile that loses its guidance system may follow an erratic path, and a river with lots of twists and bends is said to have an erratic course. Erratic can also mean "inconsistent" or "irregular". So a stock market that often changes direction is said to be acting erratically; an erratic heartbeat can be cause for concern; and if your car idles erratically it may mean that something's wrong with the spark-plug wiring.

Examples of erratic in a Sentence


My sinker has been my most erratic pitch. And when your foundation pitch is lacking, you have to go to other pitches. My sinker has been in and out, but mostly out. — Orel Hershiser, in New York Times, 9 May 1999 In winning his two-month match in Yugoslavia against Boris Spassky, 10 games to five, Bobby Fischer was erratic, which was hardly surprising considering his two-decade layoff, but there were times when he played more brilliantly than anybody could have expected. Sports Illustrated, 16 Nov. 1992 Over the centuries, in erratic ways, men have constructed a world in which they are relatively free of many kinds of threatening or harmful stimuli … — B. F. Skinner, Beyond Freedom and Dignity, (1971) 1972 so far your effort to land a summer job has been very erratic because of your erratic attendance at practice, you're in danger of being cut from the team
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Recent Examples on the Web: Adjective

Flight crews bear a lot of the responsibility for handling air rage incidents When flyers’ erratic behavior goes viral, everyone is put under a microscope, including those trying to help. Aditi Shrikant, Vox, "Why there are so many viral confrontations on airplanes," 2 Nov. 2018 But his struggles in bringing out the Model 3 during the past year and his sometimes erratic behavior have raised questions about the company’s ability to execute. Tim Higgins, WSJ, "Tesla Posts Surprising Profit on Higher Model 3 Production," 24 Oct. 2018 The company has also been plagued with one controversy after another, much of it self-inflicted as a result of Musk’s erratic behavior. Tom Krisher, The Seattle Times, "Wall Street skeptical of Tesla’s promise to post net profit," 23 Oct. 2018 The immense pressure Musk is facing may be a factor in his erratic behavior. Timothy B. Lee, Ars Technica, "Tesla stock falls on executive departures, Musk smoking weed," 7 Sep. 2018 Javier Zarracina/Vox As a president, Donald Trump can be erratic. Brian Resnick, Vox, "Donald Trump and the disturbing power of dehumanizing language," 14 Aug. 2018 On the earnings call, CEO Elon Musk apologized to analysts for his recent erratic behavior and outbursts. Recode Staff, Recode, "Recode Daily: Tesla reported its biggest-ever loss, and Elon Musk apologized," 2 Aug. 2018 State police say troopers tried to stop Steven Brooks late Thursday for erratic driving in South Strabane, about 30 miles south of Pittsburgh. Crimesider Staff, CBS News, "Police kill man wanted for slaying of Florida trombone player as she left practice," 13 Apr. 2018 Chief Deputy Randy Christian says Fields had given investigators permission to search his vehicle for drugs after he was pulled over for erratic driving. Fox News, "Officials: Man had meth packaged as Mexican candy in vehicle," 4 Apr. 2018

Recent Examples on the Web: Noun

One of the biggest boulders is now enshrined at the Erratic Rock State Natural Site in McMinnville, a small state park that aims to educate visitors about these odd erratics. Jamie Hale,, "Erratic Rock a small reminder of the big floods that shaped Oregon," 6 June 2017 Erratics are also found in the Columbia River Gorge. Jamie Hale,, "Erratic Rock a small reminder of the big floods that shaped Oregon," 6 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'erratic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of erratic


14th century, in the meaning defined at sense 1


circa 1623, in the meaning defined above

History and Etymology for erratic


Middle English, from Latin erraticus, from erratus, past participle of errare — see err


see erratic entry 1

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Statistics for erratic

Last Updated

1 Dec 2018

Look-up Popularity

Time Traveler for erratic

The first known use of erratic was in the 14th century

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More Definitions for erratic



English Language Learners Definition of erratic

: acting, moving, or changing in ways that are not expected or usual : not consistent or regular


er·​rat·​ic | \i-ˈra-tik \

Kids Definition of erratic

: not consistent or regular erratic behavior erratic movements


er·​rat·​ic | \ir-ˈat-ik \

Medical Definition of erratic 

1 : characterized by lack of consistency, regularity, or uniformity an erratic pulse

2 : deviating from what is ordinary or standard

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Comments on erratic

What made you want to look up erratic? Please tell us where you read or heard it (including the quote, if possible).


to move with a clumsy heavy tread

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