Idioms are fun phrases that mean something different from the literal words you say. People use them every day to make talking and writing much more colorful and exciting. In this lesson, you will learn a wonderful collection of idioms related to things that happen rarely, infrequently, or once in a blue moon.
In this lesson, we’ll look at idioms for once in a blue moon that mean happening rarely, very seldom, and almost never. Let’s get started and explore some of these helpful expressions.
Idioms for Once In A Blue Moon
1. Once in a blue moon
Meaning: This idiom describes an event that happens very rarely and almost never occurs.
For Example: Eating dessert before dinner is something that happens only once in a blue moon in our house. / Seeing shooting stars in the city sky happens once in a blue moon.
Other Ways to Say: Very rarely / Infrequently
2. Leap year
Meaning: This idiom describes an extra day added to February that happens only once every four years.
For Example: My birthday falls on February twenty-ninth, so I can only celebrate on my exact birthdate during a leap year. / Extra days come around during a leap year.
Other Ways to Say: Every four years / Rare calendar year
3. Pigs might fly
Meaning: This idiom means an event is completely impossible and will never happen.
For Example: Expecting him to clean his room without being asked is like saying pigs might fly. / If you think we can walk to the moon, pigs might fly.
Other Ways to Say: Never happen / Completely impossible
4. When hell freezes over
Meaning: This idiom means an event will absolutely never take place under any circumstances.
For Example: He claimed he would apologize when hell freezes over, but not today. / Expecting the cat to bark is like waiting until hell freezes over.
Other Ways to Say: Never / Absolutely not
5. Once in a lifetime
Meaning: This idiom describes a special event or chance that happens only one time across your whole life.
For Example: Seeing a total solar eclipse is a truly once in a lifetime experience. / Winning the grand prize felt like a once in a lifetime chance.
Other Ways to Say: Extremely rare / Unique opportunity
6. Seldom if ever
Meaning: This idiom means something happens on very rare occasions or almost never at all.
For Example: He is seldom if ever late for his morning soccer practice. / We seldom if ever eat fast food on school nights.
Other Ways to Say: Almost never / Rarely
7. Hardily ever
Meaning: This idiom describes an action that takes place with extreme rarity.
For Example: It snows in our town hardily ever during mild winters. / She hardily ever misses a piano practice session.
Other Ways to Say: Rarely / Scarcely ever
8. On rare occasions
Meaning: This idiom describes moments that happen infrequently rather than as a regular routine.
For Example: On rare occasions, school gets canceled because of heavy snowstorms. / We eat dessert on rare occasions after finishing homework.
Other Ways to Say: Infrequently / Sometimes
9. Few and far between
Meaning: This idiom describes wonderful things or events that are very scarce and hard to find.
For Example: Sunny days during the rainy spring season are few and far between. / Genuine antique toys at garage sales are few and far between.
Other Ways to Say: Rare / Scarcely found
10. As rare as hen’s teeth
Meaning: This idiom describes something that is completely impossible or extremely difficult to find.
For Example: Finding a four-leaf clover in the grass is as rare as hen’s teeth. / Honest answers to that trick question were as rare as hen’s teeth.
Other Ways to Say: Extremely rare / Hard to find
11. Once in a blue moon chance
Meaning: This idiom describes a special opportunity that pops up only once in a great while.
For Example: Meeting the famous astronaut was a once in a blue moon chance. / Getting free tickets to the game was a once in a blue moon chance.
Other Ways to Say: Rare chance / Unique opportunity
12. Every now and then
Meaning: This idiom means something happens occasionally, though not very often.
For Example: Every now and then, we like to bake chocolate chip cookies after dinner. / He goes to the library every now and then to borrow adventure books.
Other Ways to Say: Occasionally / From time to time
13. Every so often
Meaning: This idiom describes actions that take place intermittently with gaps of time between them.
For Example: Every so often, our family visits the mountains for a weekend hike. / She checks her plant’s soil every so often to keep it healthy.
Other Ways to Say: Occasionally / From time to time
14. From time to time
Meaning: This idiom means doing something occasionally rather than on a strict daily schedule.
For Example: From time to time, we enjoy playing board games instead of watching television. / He visits his grandparents from time to time on weekends.
Other Ways to Say: Occasionally / Every now and then
15. At odd times
Meaning: This idiom describes events or visits that happen irregularly and unpredictably.
For Example: The train schedule ran at odd times during the holiday weekend. / The puppy barked at odd times during the night.
Other Ways to Say: Irregularly / Sporadically
16. Sporadically
Meaning: This idiom or descriptive word means happening at irregular intervals rather than constantly.
For Example: Rain showers fell sporadically throughout the warm afternoon. / He practiced his drawing skills sporadically over the summer.
Other Ways to Say: Irregularly / Occasionally
17. Once in a great while
Meaning: This idiom describes an event that occurs with extreme infrequency.
For Example: Once in a great while, our family stays up late to watch a meteor shower. / We treat ourselves to ice cream once in a great while.
Other Ways to Say: Very rarely / Infrequently
18. Scarcely ever
Meaning: This idiom means an action happens with such low frequency that it is almost zero.
For Example: She scarcely ever eats candy before brushing her teeth. / He scarcely ever misses a day of school.
Other Ways to Say: Almost never / Rarely
19. Almost never
Meaning: This idiom means an event occurs on such rare occasions that it is practically absent.
For Example: It almost never hails in our town during summer months. / He almost never forgets his backpack.
Other Ways to Say: Rarely / Scarcely ever
20. Barely ever
Meaning: This idiom means an action takes place with the smallest possible frequency.
For Example: We barely ever stay up past nine o’clock on school nights. / She barely ever complains about doing chores.
Other Ways to Say: Almost never / Scarcely
21. Not in a million years
Meaning: This idiom means something will definitely never happen under any circumstance.
For Example: Not in a million years would I jump off a high cliff into the water. / He knew not in a million years would he forget his homework.
Other Ways to Say: Never / Absolutely not
22. When the stars align
Meaning: This idiom means a rare combination of lucky events must happen for something to occur.
For Example: We get to go camping only when the stars align with good weather and free weekends. / Winning the grand prize felt like when the stars align.
Other Ways to Say: By rare luck / Perfectly timed
23. Lightning strikes twice
Meaning: This idiom questions whether a rare, lucky event could possibly happen a second time.
For Example: Winning the art contest two years in a row means lightning strikes twice. / Do not expect lightning strikes twice with raffle tickets.
Other Ways to Say: Rare repetition / Second lucky break
24. Once in a millennium
Meaning: This idiom describes an event so rare that it happens only once every thousand years.
For Example: Seeing a specific planetary alignment can feel like it happens once in a millennium. / Such historic discoveries happen once in a millennium.
Other Ways to Say: Extremely rare / Thousand-year event
25. Once in a century
Meaning: This idiom describes a rare event that occurs only once every hundred years.
For Example: The giant oak tree survived a storm that came around once in a century. / Experiencing such a heavy snowstorm is a once in a century event.
Other Ways to Say: Hundred-year occurrence / Extremely rare
26. Every leap year
Meaning: This idiom jokingly refers to doing a rare task only once every four years.
For Example: Cleaning out my entire desk happens every leap year. / He offers to help with yard work every leap year.
Other Ways to Say: Very rarely / Infrequently
27. On a blue moon
Meaning: This idiom is a shortened version of describing something that happens very rarely.
For Example: Eating pizza for breakfast is something we do only on a blue moon. / Seeing him run track is on a blue moon.
Other Ways to Say: Rarely / Infrequently
28. In a blue moon
Meaning: This idiom means an occurrence that happens with extreme rarity.
For Example: Finding a twenty-dollar bill on the sidewalk happens only in a blue moon. / He cleans his bicycle in a blue moon.
Other Ways to Say: Rarely / Infrequently
29. Moon’s blue rotation
Meaning: This idiom playfully describes a rare astronomical timeline for an unusual event.
For Example: Getting everyone to agree on a movie takes a moon’s blue rotation. / Such quiet afternoons happen on a moon’s blue rotation.
Other Ways to Say: Rarely / Once in a blue moon
30. Once in a blue moon moment
Meaning: This idiom describes a special, highly infrequent experience.
For Example: Catching a glimpse of the rare bird was a once in a blue moon moment. / Snow falling in April was a once in a blue moon moment.
Other Ways to Say: Rare experience / Special occasion
31. On rare occasions only
Meaning: This idiom emphasizes that an activity is strictly limited to infrequent times.
For Example: Staying up past midnight is permitted on rare occasions only. / Eating candy is allowed on rare occasions only.
Other Ways to Say: Infrequently / Strictly rare
32. At infrequent intervals
Meaning: This idiom describes events separated by long, irregular gaps of time.
For Example: The lighthouse beacon flashed at infrequent intervals during the foggy night. / Comets appear at infrequent intervals.
Other Ways to Say: Irregularly / Sporadically
33. Periodically
Meaning: This idiom or descriptive word means happening at spaced-out intervals of time.
For Example: The teacher checked our notebooks periodically to ensure neat handwriting. / We clean out our lockers periodically.
Other Ways to Say: Occasionally / From time to time
34. Occasionally
Meaning: This idiom describes actions that take place now and then without a rigid pattern.
For Example: Occasionally, we walk to school instead of taking the yellow bus. / She occasionally reads comic books on weekends.
Other Ways to Say: Sometimes / From time to time
35. Now and then
Meaning: This idiom means doing something on casual, infrequent occasions.
For Example: Now and then, we enjoy listening to vinyl records on the old player. / He checks his garden now and then for sprouts.
Other Ways to Say: Occasionally / Sometimes
36. Here and there
Meaning: This idiom can describe rare events or scattered items appearing infrequently.
For Example: Wildflowers popped up here and there across the dry desert ground. / Finding old coins in the attic happened here and there.
Other Ways to Say: Scatters / Occasionally
37. Once in a blue moon occurrence
Meaning: This idiom describes a happening that defies normal routine because it is so rare.
For Example: A sunny day in the middle of a rainy week was a once in a blue moon occurrence. / Finding a pearl in an oyster is a once in a blue moon occurrence.
Other Ways to Say: Rare event / Unusual happening
38. Not often
Meaning: This idiom simply means something takes place with low frequency.
For Example: We do not often get snow days in our hometown during winter. / He does not often eat spicy foods.
Other Ways to Say: Rarely / Infrequently
39. Seldom seen
Meaning: This idiom describes a person, animal, or object that appears almost never.
For Example: The shy forest deer is seldom seen during daytime hours. / Vintage comic books in mint condition are seldom seen.
Other Ways to Say: Rare / Hard to find
40. Rarely ever
Meaning: This idiom emphasizes the extreme infrequency of an action.
For Example: She rarely ever makes a mistake on her spelling tests. / He rarely ever misses a free throw in basketball.
Other Ways to Say: Almost never / Scarcely
41. Once in a generation
Meaning: This idiom describes a special event or talent that appears only once every twenty or thirty years.
For Example: Discovering a comet visible to the naked eye is a once in a generation event. / That athlete’s incredible speed comes along once in a generation.
Other Ways to Say: Extremely rare / Generation event
42. Once in an epoch
Meaning: This idiom describes an event so rare that it happens across massive geological time periods.
For Example: Such massive volcanic formations erupt once in an epoch. / Discovering new prehistoric fossils happens once in an epoch.
Other Ways to Say: Extremely rare / Epoch event
43. Once in eons
Meaning: This idiom jokingly exaggerates how long it takes for a rare event to happen.
For Example: Getting my brother to clean his room feels like it happens once in eons. / Such calm weather arrives once in eons.
Other Ways to Say: Extremely rarely / Never seemingly
44. Thinly scattered
Meaning: This idiom describes rare events or objects spread out across huge gaps of time or space.
For Example: Remnants of the old stone wall were thinly scattered across the hill. / Clear sunny days were thinly scattered through autumn.
Other Ways to Say: Sparse / Rare
45. Scanty
Meaning: This idiom or descriptive word means happening in very small, rare amounts.
For Example: Information about the ancient shipwreck was scanty at best. / Rainfall during the summer drought was scanty.
Other Ways to Say: Sparse / Meager
46. Meager
Meaning: This idiom or descriptive word describes a tiny, infrequent quantity of something.
For Example: His allowance left him with meager savings for the toy. / The stray cat received meager scraps of food.
Other Ways to Say: Sparse / Scanty
47. Few in number
Meaning: This idiom describes rare items or events that have very low counts.
For Example: The remaining tickets for the school play were few in number. / Golden eagles spotted in the valley are few in number.
Other Ways to Say: Rare / Scarce
48. Scarce
Meaning: This idiom or descriptive word means something exists in very short supply.
For Example: Fresh water during the desert hike became extremely scarce. / Art supplies were scarce before the delivery truck arrived.
Other Ways to Say: Rare / Hard to find
49. Hard to come by
Meaning: This idiom means an item or event is rare and difficult to find or experience.
For Example: Vintage baseball cards in pristine condition are hard to come by. / Good advice can sometimes be hard to come by.
Other Ways to Say: Rare / Scarce
50. Rarified
Meaning: This idiom describes something exclusive, unusual, and experienced by very few people.
For Example: Winning the international championship placed her in a rarified group of athletes. / Breathing high mountain air feels rarified and fresh.
Other Ways to Say: Exclusive / Unusual
51. Once in a blue moon sighting
Meaning: This idiom describes spotting something extraordinary that rarely appears.
For Example: Seeing the rare owl in daylight was a once in a blue moon sighting. / The comet passed by as a once in a blue moon sighting.
Other Ways to Say: Rare spotting / Unusual view
52. Once in a blue moon chance meeting
Meaning: This idiom describes running into an old friend by pure, rare chance.
For Example: Bumping into my kindergarten teacher at the airport was a once in a blue moon chance meeting. / That unexpected reunion felt like a once in a blue moon chance meeting.
Other Ways to Say: Rare coincidence / Unlikely meeting
53. Once in a blue moon treat
Meaning: This idiom describes a special snack or reward given on extremely rare occasions.
For Example: Getting extra dessert on a Tuesday was a once in a blue moon treat. / Visiting the amusement park is a once in a blue moon treat.
Other Ways to Say: Rare reward / Special treat
54. Once in a blue moon surprise
Meaning: This idiom describes an unexpected event that happens only on rare occasions.
For Example: Winning the raffle ticket drawing was a once in a blue moon surprise. / Snow falling in May was a once in a blue moon surprise.
Other Ways to Say: Rare surprise / Unexpected event
55. Once in a blue moon miracle
Meaning: This idiom describes a deeply lucky, highly unusual event that saves the day.
For Example: Finding his lost wallet in the snowbank felt like a once in a blue moon miracle. / Passing the test without studying felt like a once in a blue moon miracle.
Other Ways to Say: Lucky break / Rare miracle
56. Once in a blue moon wonder
Meaning: This idiom describes something amazing that you get to witness only rarely.
For Example: The glowing bioluminescent beach waves were a once in a blue moon wonder. / Watching the rare butterfly emerge was a once in a blue moon wonder.
Other Ways to Say: Rare spectacle / Unusual marvel
57. Once in a blue moon success
Meaning: This idiom describes winning or achieving something when odds are overwhelmingly against you.
For Example: Scoring a goal from across the field felt like a once in a blue moon success. / Hitting the bullseye was a once in a blue moon success.
Other Ways to Say: Rare victory / Unlikely win
58. Once in a blue moon alignment
Meaning: This idiom describes rare conditions matching up perfectly to let something happen.
For Example: Finishing all chores early enough to play outside was a once in a blue moon alignment. / Getting all family members together took a once in a blue moon alignment.
Other Ways to Say: Perfect timing / Rare coincidence
59. Once in a blue moon adventure
Meaning: This idiom describes an exciting, unusual trip that happens only once in a great while.
For Example: Exploring the hidden cave system was a once in a blue moon adventure. / Traveling across the ocean was a once in a blue moon adventure.
Other Ways to Say: Rare journey / Special trip
60. Once in a blue moon phenomenon
Meaning: This idiom describes a natural or unusual event that occurs with extreme infrequency.
For Example: A total lunar eclipse turning the moon red is a fascinating once in a blue moon phenomenon. / Double rainbows are a lovely once in a blue moon phenomenon.
Other Ways to Say: Rare event / Unusual occurrence
Exercise to Practice
- Eating dessert before dinner is something that happens only ________ in our house.
- My birthday falls on February twenty-ninth, so I can only celebrate during a ________.
- Expecting him to clean his room without being asked is like saying ________.
- He claimed he would apologize ________, but not today.
- Seeing a total solar eclipse is a truly ________ experience.
- He is ________ late for his morning soccer practice.
- It snows in our town ________ during mild winters.
- ________, school gets canceled because of heavy snowstorms.
- Sunny days during the rainy spring season are ________.
- Finding a four-leaf clover in the grass is ________.
- Meeting the famous astronaut was a ________.
- ________, we like to bake chocolate chip cookies after dinner.
- ________, our family visits the mountains for a weekend hike.
- From time to time, we enjoy playing board games ________.
- The train schedule ran ________ during the holiday weekend.
Answer Key
- once in a blue moon
- leap year
- pigs might fly
- when hell freezes over
- once in a lifetime
- seldom if ever
- hardily ever
- on rare occasions
- few and far between
- as rare as hen’s teeth
- once in a blue moon chance
- every now and then
- every so often
- instead of watching television
- at odd times
Conclusion
Learning idioms for once in a blue moon makes describing rare events more fun and colorful. These expressions help you talk about unusual or infrequent moments in a creative way. They can make stories and everyday conversations more interesting and engaging. Using these phrases allows you to describe rare experiences naturally and clearly. Try including them when chatting with friends or writing stories at school. With practice, these idioms can make your language more expressive and lively.
