blue moon Definition
blue moon
noun
a very long time
Etymology: < a rare atmospheric condition in which layers of smoke, dust, etc., as from forest fires, volcanoes, etc., cause the surface of the moon to appear to be blue
blue moon Idioms
once in a blue moon
very seldom; almost never
blue moon Usage Examples
Adjective modifier
last: The last blue moon was in May 2002, the next is in December 2005.
Browse dictionary entries near blue moon
- ‹ blue mold
- ‹ blue line
- ‹ blue laws
- ‹ blue law
- ‹ blue jay
- ‹ blue helmets
- ‹ blue gum
- ‹ blue-green algae
- ‹ blue fox
- ‹ blue flu

