once in lifetime

USAGE SUMMARY

The phrase "once in a lifetime" is correct and usable in written English.
You can use it to describe a rare or unique opportunity that may not be repeated. For example, you could say, "The chance to go on a hot air balloon ride was once in a lifetime experience."

News & Media

Science

Wiki

Human-verified examples from authoritative sources

Exact Expressions

4 human-written examples

This is a once in lifetime opportunity to get this right, she says.

The Guardian

The lobbying and public argument was vociferous but I still wanted the best guarantees for the future safety of our city, not to mention the opportunity to examine a once in lifetime chance to remove terrible blight on the entire eastern waterfront.

Huffington Post

Second, KPNW screening rates reflect the experiences of both screened (at least once in lifetime) and never screened women.

BMC Infectious Diseases

Tell them that you're going to have a lot of fun and learn a lot more than you would staying home, and that's a once in lifetime experience.

WikiHow

Human-verified similar examples from authoritative sources

Similar Expressions

56 human-written examples

"It's unbelievable, just fantastic, a once-in-lifetime experience,"said Richard Clarke, the ship's Canadian trimmer.

The New York Times - Sports

A handful of lucky easyJet passengers today had the chance to enjoy a once-in-lifetime opportunity - a spectacular view of the total solar eclipse.

Independent

For a once-in-lifetime meal, try to get a table at legendary restaurant Arzak (arzak.info), ranked eighth in the world.

The Guardian - Travel

"A designer wedding gown may be out of budget, but this is a once-in-lifetime chance to splurge on a pair of high-fashion heels," said Cathy Schroeckenstein, the editor in chief of Weddingbee, a bridal blog.

The New York Times

Let me do it.' That's a once-in-lifetime opportunity".

Wikipedia

I felt exhilarated, like we'd witnessed a once-in-lifetime event.

Huffington Post

Traditionally, these types of once-in-lifetime experiences are only offered to small groups of wealthy donors via an auction.

Huffington Post

Expert writing Tips

Best practice

When using "once in lifetime" as a compound modifier before a noun, hyphenate the phrase to improve clarity, as in "a once-in-lifetime opportunity".

Common error

Avoid omitting the article 'a' in formal academic or business writing. While "once in lifetime" appears in headlines and news, using "once in a lifetime" is generally preferred for standard grammatical flow.

Linguistic Context

The phrase "once in lifetime" primarily functions as a compound adjective when modifying a noun like 'opportunity' or 'experience'. According to Ludwig, it serves to qualify the frequency and rarity of an event. While the standard form is "once in a lifetime", the truncated version is widely accepted in journalistic and scientific registers.

Expression frequency: Very common

Frequent in

News & Media

75%

Science

15%

Wiki

10%

Less common in

Formal & Business

5%

Reference

3%

Social Media

2%

Ludwig's WRAP-UP

In summary, "once in lifetime" is a high-impact phrase used to describe events of singular importance. While Ludwig AI notes that "once in a lifetime" is the grammatically complete version, the shortened form is prevalent in professional media and scientific literature. When using it as a modifier before a noun, remember to hyphenate it for clarity. This phrase remains one of the most effective ways to communicate the uniqueness and rarity of an opportunity across all levels of writing formality.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

once in a lifetime

Standard idiomatic version including the indefinite article for smoother flow.

once-in-a-generation

Emphasizes that the event is rare within a specific historical or age group context.

unique opportunity

Focuses on the singular nature of the chance rather than its frequency over time.

unrepeatable experience

Highlights that the event cannot be duplicated or performed again.

one-of-a-kind

A common idiomatic synonym used to describe something truly unique.

singular event

A more formal and clinical way to describe a non-recurring occurrence.

rare find

Specifically used when the subject is an object or a discovery.

once-off

British English variant emphasizing that something happens only one time.

life-changing

Focuses on the impact of the event rather than its frequency.

extraordinary

A broader adjective describing something far beyond the ordinary.

FAQs

How do I use "once in lifetime" in a sentence?

You can use it to describe a rare occurrence, such as: "This is a once in lifetime opportunity to get this right."

What is the difference between "once in lifetime" and "once in a lifetime"?

The phrase "once in a lifetime" is the standard idiom, while "once in lifetime" is a common variation often used in headlines or technical contexts for brevity.

Can I say "one-of-a-kind" instead of "once in lifetime"?

Yes, "one-of-a-kind" is a great alternative when you want to emphasize the uniqueness of an object or experience.

Is it "once in lifetime" or "once in a lifetime"?

Both are used, but "once in a lifetime" is technically more complete and preferred in formal writing.