Once in a blue moon
= very rarely; not often
A: Didn't he go out for drinking last weekend?
B: Once in a blue moon.
Refs
- All Clear 3, Helen Kalkstein Fragiadakis
idiom intermediate, 14-05-04 10:15, 14-05-04 10:17, Yosei
Learning English to be..
= very rarely; not often
A: Didn't he go out for drinking last weekend?
B: Once in a blue moon.
idiom intermediate, 14-05-04 10:15, 14-05-04 10:17, Yosei