Meanings
- not comparableSynonym of once in a blue moon (“rarely”).
Once in a purple moon, it may be necessary for the top men to settle some awful impasse between themselves.
1988, Charles Reynell (publisher), The Economist, Volume 307, Issues 7544-7556, page 112 more examples
However, in spite all of our complainings, there was a distinct pleasure in shopping along this street, because once in a purple moon, one did strike a really nice model and so very reasonable, that one wondered how the manufacturer could afford to bring it out at the price.
1924, New York Public Library, Dresses - Volumes 10-11, page 15Again, these usually show up in major currency auctions, only once in a purple moon would a dealer have one in stock.
2012, Robert J. Kravitz, A Collectors Guide to Postage and Fractional Currency, page 20Synonyms: rarely, seldom, infrequently, scarcely, seldomly, uncommonly, unoften, once in a blue moon
Synonyms & antonyms
adverbSynonym of once in a blue moon (“rarely”).
Cite this entry
once in a purple moon. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/once%20in%20a%20purple%20moon
“once in a purple moon.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/once%20in%20a%20purple%20moon. Accessed November 5, 2026.
WatkinsX Dictionary, s.v. “once in a purple moon,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/once%20in%20a%20purple%20moon.
Source: once in a purple moon on Wiktionary, CC BY-SA 4.0.