anom·​a·​ly | \ə-ˈnä-mə-lē \
plural anomalies

Definition of anomaly 

1 : something different, abnormal, peculiar, or not easily classified : something anomalous They regarded the test results as an anomaly.

2 : deviation from the common rule : irregularity

3 : the angular distance of a planet from its perihelion as seen from the sun

Keep scrolling for more

Synonyms & Antonyms for anomaly


abnormality, freak, monster, monstrosity


average, norm, normal, par, standard

Visit the Thesaurus for More 

Examples of anomaly in a Sentence

In approximately 10% of patients, autism can be explained by genetic syndromes and known chromosomal anomalies (most of which have recognizable features in addition to autism) … — Lauren A. Weiss et al., New England Journal of Medicine, 14 Feb. 2008 Eleven minutes may not sound like much when you're waiting for a table at your favorite restaurant, but in the course of centuries, eleven minutes and change become a formidable chunk of time. By the 1300s, those superfluous minutes had added up to hours, then days, then more than a week. The calendar was losing time, irrevocably, to the "real" year, slipping further and further behind in its measurement of the earth's orbit. Anomalies began to creep into what had been the certainties of life. The spring equinox—one of two moments in the year when day and night are of equal length all over the earth, and which occurs on or about March 21—began to fall on March 16, then 15, then 14. — Michelle Stacey, Harper's, December 2006 Californians aren't the only ones vexed by rolling brownouts and other power-supply anomalies. Everyday power spikes, surges, sags, and line noise cause computers, stereo equipment, televisions, telephones, and other delicate electronic equipment to go psychotic or have complete nervous breakdowns. Fortune, 25 June 2001 This policy may well have made sense back when steroid use was an anomaly. Now that bulking up with chemical help seems to be more popular than ever, it's incumbent on baseball to take action. — Steve Kettman, New York Times, 20 Aug. 2000 We couldn't explain the anomalies in the test results. her C grade is an anomaly, as she's never made anything except A's and B's before
See More

Recent Examples on the Web

As Justice Samuel Alito explains in the majority’s opinion, Abood is an anomaly in the Court’s First Amendment jurisprudence. The Editorial Board, WSJ, "The Supreme Court’s Banner Year," 27 June 2018 The extreme cold that closed the month was an anomaly in a year that witnessed its warmest February and April on record, as well as its third-warmest October. Matt Rogers, Washington Post, "D.C.’s second-warmest year on record ends with coldest December since 2010," 2 Jan. 2018 Watching Paul and his fellow inmates shooting hoops in the prison gym recently, Hargett, the P.E. teacher, said the incidents that put such boys in prison often are an anomaly in their young lives. Robert King, Indianapolis Star, "Paul Henry Gingerich: Another birthday for a boy in prison," 17 Feb. 2015 Russia was an anomaly, a surprise quarterfinalist with two players competing outside its mid-level home circuit. Steven Goff,, "'Hard-working, compact, united and well-organized': The World Cup's surprising final four," 8 July 2018 Williams and her Illinois net neutrality bill are not an anomaly. Cathy Cunningham,, "Can net neutrality be saved in Illinois?," 5 July 2018 Take a look at the league average numbers, alongside Brantley’s present stats: Brantley’s skill set is an anomaly in today’s game, and becoming more so all the time. Staff,, "Nine Innings: Solving the Yankees' Sonny Gray Problem, AL East Deciding Factors and Our Favorite Statcast Quirks," 2 July 2018 Going back further, cover songs reaching rock airplay charts is not an anomaly in recent months. Kevin Rutherford, Billboard, "Weezer's 'Africa' & Bad Wolves' 'Zombie' Lead Rock Radio's Cover Craze," 13 June 2018 After the Blue Jays limited Maryland to eight goals in four quarters and three overtime periods on Saturday, coach Dave Pietramala was hopeful that the defense’s showing was not an anomaly. Edward Lee,, "What we learned from the Big Ten men’s lacrosse tournament semifinals," 4 May 2018

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

See More

First Known Use of anomaly

1603, in the meaning defined at sense 3

History and Etymology for anomaly

see anomalous

Keep scrolling for more

Learn More about anomaly

Statistics for anomaly

Last Updated

30 Oct 2018

Look-up Popularity

Time Traveler for anomaly

The first known use of anomaly was in 1603

See more words from the same year

Keep scrolling for more

More Definitions for anomaly



English Language Learners Definition of anomaly

: something that is unusual or unexpected : something anomalous


anom·​a·​ly | \ə-ˈnä-mə-lē \
plural anomalies

Kids Definition of anomaly

: something different, abnormal, strange, or not easily described


anom·​a·​ly | \ə-ˈnäm-ə-lē \
plural anomalies

Medical Definition of anomaly 

: a deviation from normal especially of a bodily part the infants demonstrated congenital anomalies personality anomalies

Keep scrolling for more

Comments on anomaly

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


something that serves to warn or remind

Get Word of the Day daily email!

Test Your Vocabulary

Difficult Vocab Quiz

  • the-education-of-achilles-eugne-delacroix
  • Which is a synonym of discomfit?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!