Definition of blue moon
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 moon — Saturday Review>
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>
First Known Use of blue moon
Rhymes with blue moon
aswoon, attune, baboon, balloon, bassoon, buffoon, Calhoun, Cancún, cardoon, cartoon, cocoon, commune, doubloon, dragoon, festoon, fine-tune, forenoon, full moon, gaboon, gadroon, galloon, Gudrun, half-moon, harpoon, high noon, immune, impugn, jargoon, jejune, Kowloon, Kunlun, lagoon, lampoon, lardoon, Maine coon, maroon, monsoon, Neptune, new moon, oppugn, Pashtun, patroon, platoon, poltroon, pontoon, premune, puccoon, quadroon, ratoon, repugn, rough-hewn, saloon, Sassoon, shalloon, soupspoon, spittoon, spontoon, teaspoon, tribune, triune, tuchun, tycoon, typhoon, untune, Walloon
Learn More about blue moon
Thesaurus: All synonyms and antonyms for "blue moon"
Seen and Heard
What made you want to look up blue moon? Please tell us where you read or heard it (including the quote, if possible).