erratic
Americanadjective
-
deviating from the usual or proper course in conduct or opinion; eccentric.
erratic behavior.
- Synonyms:
- capricious, unstable, unpredictable
- Antonyms:
- stable, regular, consistent
-
inconsistent, irregular, or unpredictable.
Many factors affect purchasing power, such as inflation and erratic swings in the stock market.
-
having no certain or definite course or pattern; wandering; not fixed.
erratic winds.
-
Geology. noting or pertaining to a boulder or the like carried by glacial ice and deposited some distance from its place of origin.
-
(of a lichen) having no attachment to the surface on which it grows.
noun
-
an erratic or eccentric person.
-
Geology. an erratic boulder or the like.
adjective
-
irregular in performance, behaviour, or attitude; inconsistent and unpredictable
-
having no fixed or regular course; wandering
noun
-
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
-
an erratic person or thing
Other Word Forms
Derived Forms
Etymology
Origin of erratic
First recorded in 1325–75; Middle English, from Latin errāticus, equivalent to errāt(us) (past participle of errāre “to make a mistake, err” ( see err) + -icus -ic
Explanation
The adjective erratic describes things that are unpredictable, unusual, and that deviate from the norm. An erratic quarterback might completely confuse his receivers waiting for a pass. Like its linguistic relative, error, the adjective erratic means "deviating from the norm," or "wrong." It also implies behavior or qualities that are unpredictable or odd. The word comes from the Latin verb errare, or "to wander" off course. In the field of geology, a rock that is erratic is unlike others in its environment because it has been transported by glacial activity. Likewise, someone driving a car that veers out of its lane is said to be driving erratically.
Vocabulary lists containing erratic
To Kill a Mockingbird
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List 1
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"To Kill a Mockingbird" by Harper Lee, Chapters 1–6
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Appeared in the April 7, 2026, print edition as 'Allies Are Worried They Are Tied to an Erratic U.S.'.
From The Wall Street Journal • Apr. 7, 2026
I settled on a quesadilla quest and tried one stuffed with carne asada from Erratic Tacos in the Beer Barn.
From Los Angeles Times • Apr. 16, 2024
Erratic eating patterns, including late-night meals, have been linked to weight gain and a greater risk of metabolic disease.
From Salon • Aug. 3, 2023
"Erratic stress test capital requirements and constant uncertainty around future regulations damage the banking system without making it safer," he added.
From BBC • Apr. 4, 2023
Erratic masses of this kind have been known to fall in all ages and in all countries, and are of frequent occurrence.
From Nature and Culture by Rice, Harvey
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
