Once in A Blue Moon

IDIOM OF THE DAY – Once in a Blue Moon

Imagining you are getting into a conversation with your friend maybe the topic is about how often we go to a cinema? Then your friend just said: “Once in a blue moon” and you wondered yourself that what is once in a blue moon? The question was about the frequency of going to a cinema, and he answered about the moon?! It is so weird.
However, his response is absolutely proper as he used a great idiom that I can’t wait to share with you today!

ONCE IN A BLUE MOON
Meaning: Very rarely, seldom
The phrase refers to something that happens very infrequently.
When we say that something happens once in a blue moon, what we mean is that it happens very rarely.

History of idiom:
The ‘moon’ in this idiom does, in fact, refer to the real moon when it is full. There are generally three full moons in a season, although sometimes there may be four. The third full moon visible on the rare occasions that there are four in a season is known as a ‘blue moon’. But why blue? Surprisingly, a blue moon doesn’t refer to the actual color of the moon.
It is interesting that the word derives from the Old English word ‘belewe’, which had two separate meanings. One of them was ‘blue’. The other was ‘betrayer’.
Many years ago, before the Gregorian calendar was reformed, the church used to calculate the date that Easter would take place that year on the cycle of the moon.
When a ‘blue moon’ appeared in the sky, the clergy needed to warn people that this did not represent the end of Lent and therefore bring an end to fasting, but was, in fact, a ‘betrayer moon’!

Example:
“Once in a blue moon, I go to the cinema, only when there’s a film I really want to see.”
“I’m very careful about what I eat so it’s only once in a blue moon I eat fast food.”
”Because I live abroad, I get to see my parents once in a blue moon.”

I hope this useful idiom will help you increase your score in IELTS speaking.

Also check :

• Idioms for IELTS Speaking