Once in a Blue Moon

Meaning Of Idiom ‘Once in a Blue Moon’ Once in a blue moon means not very often; very rarely; only once in a long period of time; practically never. 1Heacock, Paul. Cambridge Dictionary of American Idioms. Cambridge: Cambridge UP, 2010. ,2Ammer, Christine.  American Heritage Dictionary of Idioms. Boston: Houghton Mifflin Harcourt, 2013. ,3Kirkpatrick, Elizabeth M. The … Read more