blue moon
noun
a second full moon in a month, occurring every two to three years as a result of the discrepancy between a lunar year and a solar year.
blue moons
-
pluralof blue moon.plural
The grammatical form denoting more than one person, place, thing, or idea.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
On average, blue moons occur about every two or three years, according to NASA.
From Los Angeles Times ● Aug. 19, 2024
As blue moons are not that common, it's thought where the phrase "once in a blue moon" comes from.
From BBC ● Aug. 19, 2024
Each month usually hosts only one full moon, but blue moons sometimes arise because the lunar cycle is 29.5 days long — just short of the length of an average calendar month.
From New York Times ● Aug. 29, 2023
For these once-cursed Clippers, pigs are flying, blue moons are out, and the monkey is finally off their back.
From Washington Post ● Jun. 19, 2021
I refuse to let myself believe, for I have never seen blue moons.
From A Chair on the Boulevard by Leonard Merrick
