Idiom Topics
The Ubiquitous Essentials
10- On the other hand
- At the end of the day
- In the long run
- Bear in mind
- A piece of cake
- Keep an eye on
- Out of the blue
- Rule of thumb
- So far, so good
- Behind the scenes
Everyday Casual & Workplace
10- Under the weather
- Call it a day
- Up in the air
- Wrap your head around
- Break the ice
- Get out of hand
- Go the extra mile
- Touch base
- Hit the nail on the head
- Cut corners
Problem Solving & Interaction
10- See eye to eye
- Read between the lines
- Take it with a grain of salt
- Get the hang of it
- Give the benefit of the doubt
- The elephant in the room
- Hit the ground running
- Play it by ear
- Bite the bullet
- Sit on the fence
Decisions & Perspectives
9- Jump on the bandwagon
- Cross that bridge when we come to it
- The best of both worlds
- A blessing in disguise
- Once in a blue moon
- Pull someone's leg
- Miss the boat
- Better late than never
- Get your act together
Colorful & Traditional
10- Spill the beans
- Let the cat out of the bag
- Bite off more than you can chew
- Go back to the drawing board
- Barking up the wrong tree
- Actions speak louder than words
- A penny for your thoughts
- Break a leg
- Hit the sack
- Beat around the bush
Academic & Formal Discourse
10- Bear fruit
- Pave the way
- Shed light on
- Go hand in hand
- Tip the scales
- Fly in the face of
- Bring to the table
- Turn a blind eye
- Draw a blank
- State of the art
Emotions & Reactions
10- Over the moon
- Down in the dumps
- On edge
- Blow off steam
- Keep your cool
- Drive someone up the wall
- On cloud nine
- A weight off my shoulders
- At your wits' end
- Thrilled to bits
Effort, Success, & Failure
10- Start from scratch
- Pass with flying colors
- Fall flat
- Go down the drain
- Keep your head above water
- Pay off
- Throw in the towel
- Make headway
- Uphill battle
- Back to square one
Time, Speed, & Urgency
10- Beat the clock
- At the eleventh hour
- Around the clock
- In the nick of time
- Drag your feet
- Time flies
- Make up for lost time
- Call time on
- Ahead of the curve
- On the spur of the moment
Resources, Money, & Value
10- Make ends meet
- Foot the bill
- Break the bank
- Tighten your belt
- Bang for your buck
- A drop in the ocean
- Make a killing
- On a shoestring budget
- Worth your weight in gold
- Pay top dollar
Once in a blue moon
Learn the meaning, origin, and usage of the idiom "Once in a blue moon" with five example sentences across different contexts. This idiom is part of ourDecisions & Perspectives collection for PTE and IELTS preparation.
Once in a blue moon
An event that happens very rarely or almost never.
History & Origin
The phrase originally dates back to the 16th century, where it was used as a proverb for absolute impossibility, akin to saying 'the moon is made of green cheese.' Over time, its meaning shifted from 'never' to 'highly unusual' due to actual astronomical events. In modern astronomy, a 'blue moon' refers to the rare occurrence of a second full moon within a single calendar month, which only happens about once every 2.7 years.
Examples
My brother lives all the way in Vancouver, so we only get to see each other once in a blue moon.
While our main servers operate seamlessly, we do experience a minor system glitch once in a blue moon that requires a quick reboot.
Such economic anomalies occur only once in a blue moon, making them difficult for researchers to study using standard predictive models.
It is once in a blue moon that a rookie player captures the championship title in their debut season, but tonight we witnessed history.
Opportunities to drastically restructure our city's green infrastructure come along once in a blue moon, and we must seize this moment.
Quiz
Which of the following sentences uses the idiom correctly?
A. I need to buy groceries once in a blue moon because my refrigerator is completely empty today.
B. Because she loves coffee, she visits her favorite local café once in a blue moon before heading to work.
C. Although the professor is known for being incredibly strict, he praises a student's essay once in a blue moon.
D. You must brush your teeth once in a blue moon if you want to prevent cavities and maintain good dental hygiene.