Once in a Blue Moon - Meaning, Definition & Synonyms 

Where Did the Idiom the Once in a Blue Moon Come From?

The idiom 'Once in a Blue Moon' originates from the rare happening of a second full moon that appears in a calendar month. This unusual event occurs at least once every two to three years, and that is why the phrase shows that it is a rare happening.

Scenarios to Use the Idiom ‘Once in a Blue Moon’

Scenario 1:

Social Gatherings

• Scenario: Your friend invites you to a birthday celebration, and you mention how rare it is for you to attend because of the workload.
• Use: "I usually go to parties once in a blue moon, because of my workload. That is why I look forward to attending this one!

Scenario 2:

Work or School Events

• Scenario: You rarely take an off at work.
• Use: "I generally take a day off work once in a blue moon."

Practice Exercise

Now that you have learned all about the idiom, ‘Once in a Blue Moon,’ let us practice some multiple-choice questions based on it!

Multiple-Choice Questions

1. What does the idiom "once in a blue moon" mean?

a) Frequently
b) Never
c) Rarely
d) Always

2. Which sentence correctly uses the idiom "once in a blue moon"?

a) She eats chocolate once in a blue moon because she loves it so much.
b) He visits his grandparents once in a blue moon since they live nearby.
c) They watch movies once in a blue moon because they have a lot of free time.
d) I go hiking once in a blue moon because I rarely get the chance.

3. If someone says, "I only cook fancy meals once in a blue moon," what do they mean?

a) They cook fancy meals very often.
b) They never cook fancy meals.
c) They cook fancy meals rarely.
d) They always cook fancy meals.

4. Why might someone say, "Opportunities like this come once in a blue moon"?

a) The opportunity is very common.
b) The opportunity is very rare.
c) The opportunity happens all the time.
d) The opportunity never happens.

5. "My friend only calls me once in a blue moon." What does this suggest about their calls?

a) The friend calls very frequently.
b) The friend calls very rarely.
c) The friend never calls.

d) The friend always calls.

Answer Key

Here are the answers to the Multiple-Choice Questions of the ‘Once in a Blue Moon’ idiom!

1. c) Rarely
2. d) I go hiking once in a blue moon because I rarely get the chance.
3. c) They cook fancy meals rarely.
4. b) The opportunity is very rare.
5. b) The friend calls very rarely.

The importance of idioms like ‘Once in a Blue Moon’ in the IELTS exam cannot be ignored! Using idioms in your IELTS speaking and writing tasks can boost your score and make your language sound more engaging. However, it's also important to use them appropriately and make them fit naturally within the context.