blue moon

noun

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 Rev.
2 : a second full moon in a calendar month

Examples of blue moon in a Sentence

  1. once in a blue moon we'll get dressed up and eat in a fancy restaurant

First Known Use of blue moon

1821

blue moon Synonyms



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