blue moon


Definition of blue moon

1 : a very long period of time usually used in the phrase once in a blue moonsuch people happen along only once in a blue moonSaturday Rev.
2 : a second full moon in a calendar month

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Synonyms for blue moon


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Examples of blue moon in a Sentence

once in a blue moon we'll get dressed up and eat in a fancy restaurant
Recent Examples on the Web With thirteen full moons, two supermoons, and a blue moon during 2020, skygazers have plenty of celestial beauty to look forward to this year. Isabel Garcia, House Beautiful, "Bundle Up—A Full "Snow Moon” Is Coming February 8," 3 Feb. 2020 Here’s what else to know about the upcoming total lunar eclipse, supermoon and blue moon. Melissa Chan, Time, "A Rare Blue Moon Lunar Eclipse That Hasn't Been Seen in 35 Years Is Coming Soon. Here's What You Need to Know," 10 Jan. 2018 The second full moon in a month is called a blue moon, and the second new moon is called a black moon. David Allan, CNN, "A black moon is coming on July 31. Here's what that means," 30 July 2019 On his day, the Frenchman is the complete midfielder, but that day is occurring once in a blue moon at the moment, and has been for some time., "Ranking the 16 Winners of the Golden Boy Award," 16 Oct. 2019 In this sense, a black moon is like the evil twin of a blue moon, conventionally understood as the second full moon in a month. Michael Greshko, National Geographic, "What is a 'black moon', and how often does one happen?," 31 July 2019 The next blue moon won’t glow in the sky until Oct. 31, 2020. Richard Lederer, San Diego Union-Tribune, "Our language is moonstruck with lunar words," 3 Aug. 2019 The second full moon in a month is called a blue moon, and the second new moon is called a black moon. Wire Service, The Mercury News, "A black moon is coming tonight. Here’s what that means.," 31 July 2019 The green clovers, pink hearts, blue moons and yellow stars are infused with vanilla flavoring and plenty of sugar. Hannah Chubb,, "You Can Now Buy Bags of Oversized Lucky Charms Marshmallows Because Dreams Do Come True," 9 Aug. 2019

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

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First Known Use of blue moon

1821, in the meaning defined at sense 1

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Time Traveler for blue moon

Time Traveler

The first known use of blue moon was in 1821

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Statistics for blue moon

Last Updated

11 Feb 2020

Cite this Entry

“Blue moon.” Dictionary, Merriam-Webster, Accessed 19 Feb. 2020.

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Rhyming Dictionary: Words that rhyme with blue moon

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