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Synonyms

err

American  
[ur, er] / ɜr, ɛr /

verb (used without object)

  1. to go astray in thought or belief; be mistaken; be incorrect.

  2. to go astray morally; sin.

    To err is human.

    Synonyms:
    lapse, transgress
  3. Archaic. to deviate from the true course, aim, or purpose.


idioms

  1. err on the side of caution. see err on the side of caution.

err British  
/ ɜː /

verb

  1. to make a mistake; be incorrect

  2. to stray from the right course or accepted standards; sin

  3. to act with bias, esp favourable bias

    to err on the side of justice

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • errability noun
  • errable adjective

Etymology

Origin of err

First recorded in 1275–1325; Middle English erren, from Old French errer, from Latin errāre “to make a mistake; wander”; akin to Gothic airzjan, Old High German irrôn ( German irren )

Explanation

When you err, you make a mistake or do something wrong. When a newspaper reporter errs in a printed story, the paper often prints a correction the next day. By itself, err, which shares a Latin root with error, is a formal way to say "mess up." The proverb "To err is human, to forgive divine" is an old-fashioned version of "Hey, everyone makes mistakes. Why don't you be the bigger person and let it go?" Err can also mean to go in a certain direction, as in another common saying, "Err on the side of caution," or "Play it safe."

Keep Reading on Vocabulary.com

Vocabulary lists containing err

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.

People don’t know how long they will live, so they err on the side of caution.

From MarketWatch • Apr. 16, 2026

“I tend to want to always err on the side of sending out more information than less,” Ghilarducci said.

From Los Angeles Times • Mar. 24, 2026

Based on her forecast, the Fed could err on the side of patience as it assesses the impact of recent rate reductions, Hammack said Tuesday at an event in Ohio on banking and monetary policy.

From The Wall Street Journal • Feb. 10, 2026

“The guidelines err in promoting meat and dairy products, which are principal drivers of cardiovascular disease, diabetes, and obesity,” Neal Barnard, president of the Physicians Committee for Responsible Medicine, said in a statement.

From Barron's • Jan. 7, 2026

Outside at the edge of the runway, Queenie, err whatever her name was, stood staring at the wreck of the Luftwaffe bomber.

From "Code Name Verity" by Elizabeth Wein