blue moon

noun

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

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
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 next seasonal blue moon won't take place until May 2027. John Tufts, The Indianapolis Star, 7 Aug. 2024 Tuesday’s moon followed the Aug. 19 super blue moon. Jaweed Kaleem, Los Angeles Times, 17 Sep. 2024 About 25% of all full moons are supermoons, while only 3% of full moons are considered blue moons. John Tufts, The Courier-Journal, 17 Sep. 2024 There are two types of blue moons: seasonal and monthly. Doyle Rice, The Indianapolis Star, 17 Aug. 2024 See all Example Sentences for blue moon 

Word History

First Known Use

1821, in the meaning defined at sense 1

Time Traveler
The first known use of blue moon was in 1821

Dictionary Entries Near blue moon

Cite this Entry

“Blue moon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/blue%20moon. Accessed 22 Nov. 2024.

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!