# blue moon

idiom

Source: https://englishreference.com/idiom/blue-moon
Updated: 2026-08-10

## Meaning

A long time.

## Examples

- I have not seen him in a blue moon.
- It has been a blue moon since we last visited our old family home in the countryside.
- After a blue moon spent traveling through distant lands, the explorer finally returned to find his hometown completely transformed by time.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.