anomaly

noun

anom·​a·​ly ə-ˈnä-mə-lē How to pronounce anomaly (audio)
plural anomalies
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

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
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The worry was that, in 2025, with a new regime in the White House and a sympathetic Congress, the struggles of the previous year could be not an anomaly but a template for the time ahead. Nathan Heller, The New Yorker, 3 Mar. 2025 As a filmmaker leading a motion picture label, Gunn is an anomaly among studio bosses in town. Anthony D'alessandro, Deadline, 24 Feb. 2025 When the man arrived at the Ysleta port of entry, officers completed a Low Energy Portal scan and noticed anomalies in the way the vehicle looked. Saleen Martin, USA TODAY, 24 Feb. 2025 Updated at 10:15 am EST to clarify the nature of the booster anomaly on the second Vulcan rocket. Ars Technica, 21 Feb. 2025 See All Example Sentences for anomaly

Word History

Etymology

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

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Cite this Entry

“Anomaly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/anomaly. Accessed 9 Mar. 2025.

Kids Definition

anomaly

noun
anom·​a·​ly ə-ˈnäm-ə-lē How to pronounce anomaly (audio)
plural anomalies
1
: an act or instance of not following the general rule or method
2
: something anomalous : something different, abnormal, strange, or not easily described

Medical Definition

anomaly

noun
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

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