blue moon
名词
UK/ˌbluː ˈmuːn/
US/ˌbluː ˈmuːn/
定义 blue moon 名词
- Countableenvironment
The second full moon that appears in a single calendar month, an event occurring approximately every two and a half years.
The occurrence of a blue moon is infrequent; when will the next one appear?
Despite its name, a blue moon does not actually appear to be blue in color.
Astronomers predict that the next blue moon will occur next year.
成语
- once in a blue moon
Describes something that happens very rarely or infrequently.
• I live in the city center, so I go to the countryside once in a blue moon.