anom·​a·​ly ə-ˈnä-mə-lē How to pronounce anomaly (audio)
plural anomalies
: something different, abnormal, peculiar, or not easily classified : something anomalous
They regarded the test results as an anomaly.
: deviation from the common rule : irregularity
: the angular distance of a planet from its perihelion as seen from the sun

Did you know?

You might be familiar with the Greek word homos, which means "same." It is from this word that we get words like homonym, homogeneous, and homophone, all of which have to do with sameness or similarity. What does this have to do with anomaly? Although it's not obvious, homos is a part of the etymology of anomaly, too. Anomaly is a descendant of the Greek word anōmalos, which means "uneven" or "irregular." Anōmalos comes from the prefix a- (meaning "not") and the word homalos (meaning "even")—and homalos comes from homos.

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 For every anomaly presented by COPA, Wright supplied an explanation. Joel Khalili, WIRED, 14 Feb. 2024 Virgin Galactic Virgin Galactic reported an anomaly on its most recent flight, Galactic 06, which took place 12 days ago from a spaceport in New Mexico. Eric Berger, Ars Technica, 6 Feb. 2024 Some people pursue late abortions with wanted pregnancies, having just found out their fetuses have grave anomalies. Maggie Shannon, The New Yorker, 5 Feb. 2024 One of the anomalies in this year’s nominations is that the Best Música Urbana Album category had only three names in it. Tomás Mier, Rolling Stone, 5 Feb. 2024 The group of underwater archaeologists recently spotted an anomaly in the Pacific Ocean — more than 16,000 feet underwater — that resembles a small aircraft. Alexandra Banner, CNN, 31 Jan. 2024 That’s not an anomaly — Californians consistently pay more for gas than the rest of the country. Wire Service, The Mercury News, 29 Jan. 2024 The White Mountain Range seems an anomaly when first glimpsed. Paul McHugh, Sacramento Bee, 31 Jan. 2024 The term encompasses a broad range of encounters and data anomalies, many of which end up having innocuous origins. Eleanor Watson, CBS News, 25 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'anomaly.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from Middle French and Latin; Middle French anomalie "irregularity in grammar," borrowed from Latin anōmalia, borrowed from Greek anōmalía "unevenness, inequality, inconsistency," from anṓmalos "not uniform, unequal, inconsistent, anomalous" + -ia -y entry 2

First Known Use

1585, in the meaning defined at sense 2

Time Traveler
The first known use of anomaly was in 1585


Dictionary Entries Near anomaly

Cite this Entry

“Anomaly.” Dictionary, Merriam-Webster, Accessed 22 Feb. 2024.

Kids Definition


anom·​a·​ly ə-ˈnäm-ə-lē How to pronounce anomaly (audio)
plural anomalies
: an act or instance of not following the general rule or method
: something anomalous : something different, abnormal, strange, or not easily described

Medical Definition


anom·​a·​ly ə-ˈnäm-ə-lē How to pronounce anomaly (audio)
plural anomalies
: a deviation from normal especially of a bodily part
the infants demonstrated congenital anomalies
personality anomalies

More from Merriam-Webster on anomaly

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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