Slang & idioms
"once in a blue moon", drawn literally
Literally

once in a blue moon

(phrase)Neutral

What it actually means

Very rarely. Used to emphasize how seldom something happens.

In a sentence

  • “I only see my cousins once in a blue moon.”
  • “He calls his mom once in a blue moon, even though he means to call more.”

Also known as

rarelyhardly ever

Where it’s used

everyday

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More idioms like this

once in a blue moon — American slang definition + audio