erratic

American  

[ih-rat-ik] / ɪˈræt ɪk /

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.

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noun

1. an erratic or eccentric person.

2. Geology. an erratic boulder or the like.

erratic British  

/ ɪˈrætɪk /

adjective

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

2. having no fixed or regular course; wandering

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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

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” ( err ) + -icus -ic

Example Sentences

The erratic Chinese air activity has created uncertainty about Beijing’s intentions amid global events.

From The Wall Street Journal

By age 5, in 1951, I began to notice that her behavior could be erratic.

From The Wall Street Journal

But after looking erratic in his driving for most of the session, Antonelli composed himself for his final run and put the car where it deserved to be on the front row.

From BBC

But owing to his erratic behavior, one never knows when he will strike next.

From The Wall Street Journal

But the erratic Arctic temperatures plunged again to more than – 50°F. Three of the crew members returned barely coherent; the other four were unable to move, stranded miles away from the ship.

From Literature

Related Words

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