Meantime vs Mean Time: Which One Should You Use?

You’re writing an email and stop at one phrase: “in the meantime” or “in the mean time”? The two spellings look almost identical, but they aren’t interchangeable.

This guide covers what each form means, when to use it, and how to avoid the mistake. You’ll also find examples, synonyms, a quick editing rule, and a short FAQ.

Table of Contents

Meantime or Mean Time: The Quick, Accurate Answer

Use “meantime” (one word) when you mean “while we wait” or “during the gap between two events.” It is the standard spelling in phrases like “in the meantime.”

Use “mean time” (two words) only in technical contexts. Examples are Greenwich Mean Time (GMT), mean solar time, and reliability terms such as “mean time between failures.”

If you’re unsure, you almost certainly want the one-word version.

Meantime vs Mean Time: Key Differences

Feature	Meantime	Mean Time
Spelling	One word	Two words
Part of speech	Noun or adverb	Adjective + noun
Core meaning	The period between two events	An averaged or standardized measure of time
Typical phrase	in the meantime	Greenwich Mean Time
Where you see it	Emails, conversation, general writing	Astronomy, timekeeping, engineering
Tone	Everyday, neutral	Technical

What Meantime Means in Modern English

Meantime Meaning Explained Simply

“Meantime” refers to the stretch of time between now and a future event. It answers the question “What happens while we wait?”

Think of a train that arrives in ten minutes. Everything you do until it shows up happens in the meantime.

Meantime Usage in Sentences

Here are the most common patterns:

In the meantime, … The most common form, usually opening a sentence.
Meantime, … A shorter adverb version, common in news writing and storytelling.
For the meantime Used to mean “for now,” though some editors prefer “for the time being.”

Examples:

The software update will take an hour. In the meantime, you can keep reading.
The contractor is late. Meantime, we’ve moved the furniture out of the room.
Your order ships Friday. In the meantime, here’s your tracking link.

Is Meantime One Word or Two?

In modern English it’s one word. You’ll still see “in the mean time” in older texts and casual writing. Current style guides and most editors treat the one-word form as correct.

Mean Time Meaning and Technical Usage

Definition

In its two-word form, “mean” is an adjective meaning “average” or “middle.” Mean time is time worked out from an average, not from the exact position of the sun on a given day.

The sun’s apparent motion varies through the year, so astronomers invented a smoothed-out average day. That average is mean solar time.

Where Mean Time Is Correct

You’ll use the two-word form in these settings:

Greenwich Mean Time (GMT): the mean solar time at the Greenwich meridian in London.
Local mean time: the average solar time at a specific place, used before standard time zones.
Mean solar time: the standard astronomy term.
Engineering terms: mean time between failures (MTBF) and mean time to repair (MTTR).

In none of these does “mean time” describe a waiting period. It’s a measurement or an average.

Meantime vs Mean Time: Understanding the Difference

The difference comes down to function. “Meantime” describes when something happens relative to other events. “Mean time” describes what kind of time is being measured.

Meantime or Mean Time Difference at a Glance

“I’ll finish the report. In the meantime, grab a coffee.” (a waiting period)
“The meeting is at 9:00 a.m. Greenwich Mean Time.” (a time standard)
“Our server’s mean time between failures is 40,000 hours.” (a statistical average)

Ask yourself one question: Am I talking about a gap in time, or a measurement of time? A gap takes “meantime.” A measurement takes “mean time.”

Why Writers Get Confused

Similar Sound, Different Meaning

Spoken aloud, the two are nearly identical. The stress falls slightly differently, but in fast speech you can’t hear the gap. Nothing in your ears tells you which spelling to use.

Spacing Changes Meaning

A single space turns an everyday word into a technical term. That’s easy to miss when you’re typing quickly. “In the mean time” looks plausible because both words exist on their own, and that’s what makes the slip so common.

Spellcheck Is Not Reliable Here

Spellcheck looks for misspelled words, and “mean” and “time” are both spelled correctly. Grammar tools may or may not flag the error, so a human read-through is the safer check. Don’t assume the green light means you’re right.

Mean Time or Meantime Synonym

If you want variety, or the phrase has appeared three times already, try these alternatives.

Synonyms for “in the meantime”:

Meanwhile
For now
For the time being
In the interim
Until then
While you wait
In the intervening time

Synonyms for the technical “mean time”:

Average time
Mean solar time
Standard time (in some contexts)

Note that the two lists don’t overlap, which is a useful reminder that the terms mean different things.

Historical Origin of Meantime and Mean Time

Where Meantime Comes From

“Meantime” has been in English since the Middle English period, around the 14th century. It was built from “mean,” meaning “middle” or “intermediate,” plus “time.” So it literally means an in-between time.

The “mean” here has nothing to do with being unkind. It comes from the same root as “median” and “medium.”

READ THIS: Cancelled or Canceled: Correct Spelling, Meaning & Examples

Why Mean Time Stayed Separate

The two-word form stayed in scientific and technical writing, where “mean” kept its sense of “average.” Its use grew in the 1800s when railways pushed countries toward standardized time. Britain adopted Greenwich Mean Time for its railways, and many other regions soon followed.

So the same ancestor word split into two paths. One became an everyday word for waiting. The other stayed a precise term for averages.

Meantime in British English vs American English

Is There a Difference?

Not in any meaningful way. Both British and American writers use “in the meantime” as the standard form.

The only difference is frequency in related terms. “Meanwhile” is a little more common in everyday American writing, while “in the interim” shows up more in formal British and legal text. Neither affects which spelling is correct.

In the Meantime vs In the Mean Time

Which One Is Correct?

“In the meantime” is correct. It’s the form modern dictionaries list and the one editors expect.

“In the mean time” appears in older writing and still turns up today. Most current style guidance treats it as an error or at least outdated, so avoid it in professional work.

Version	Verdict
In the meantime	✅ Correct and standard
In the mean time	⚠️ Older or nonstandard; avoid
Greenwich Mean Time	✅ Correct (technical term)
Greenwich Meantime	❌ Incorrect

Mean Time or Meantime Examples

Correct “meantime” examples:

The plumber arrives at noon. In the meantime, please avoid using the kitchen sink.
Results take two days. Meantime, rest and drink plenty of water.
We’re finalizing the contract. In the meantime, our team will begin onboarding.
The bridge is closed for repairs, so in the meantime, use the northern route.

Correct “mean time” examples:

The flight departs at 14:00 Greenwich Mean Time.
Local mean time varied from town to town before time zones existed.
The device has a mean time between failures of 50,000 hours.
Astronomers rely on mean solar time to keep observations consistent.

Everyday English Usage and Real Examples

Email and Professional Writing

In workplace messages, “in the meantime” is a polite bridge. It tells the reader you’re taking action while they wait.

“I’ll send the revised draft tomorrow. In the meantime, please review the attached outline.”
“The vendor is still confirming pricing. In the meantime, we can finalize the schedule.”

It signals progress, which makes it a handy phrase in project updates and customer replies.

Formal vs Informal English

The phrase works in both registers, but the shorter forms change the feel.

Formal: “In the interim, the committee will continue its review.”
Neutral: “In the meantime, the committee will continue its review.”
Informal: “Meanwhile, the committee’s still reviewing.”

Use “mean time” in formal writing only when you’re naming a time standard or a technical metric.

Common Mistakes and How to Avoid Them

Frequent Errors

Splitting the word: writing “in the mean time” for a waiting period.
Joining the technical term: writing “Greenwich Meantime.”
Using “for the mean time”: the usual idiom is “for the time being” or “for the meantime.”
Mixing in “mean”: assuming the word has something to do with being unkind.
Trusting spellcheck: letting software decide for you.

A Simple Editing Rule

Try this swap test: replace the phrase with “meanwhile” or “for now.” If the sentence still makes sense, use “meantime.” If it doesn’t, and you’re talking about a clock standard or an average, use “mean time.”

Search Trends and Real Usage Data

Search interest in this topic tends to be steady and question-driven. People usually look it up right when they’re writing, so the queries are practical: “meantime or mean time,” “in the meantime or in the mean time,” and “is it meantime one word.”

I didn’t pull live search-volume numbers for this article. For exact figures, check a tool like Google Trends or your preferred keyword platform. What the pattern of questions does suggest is that most readers want a fast answer and a quick example, not a long lecture. That’s why the featured-snippet-style answer sits at the top of this guide.

Keyword Variations and Writing Intent

People reach this topic with different goals, and the wording of their query usually shows which one.

Correctness intent: “meantime or mean time,” “in the meantime or in the mean time”
Definition intent: “what does meantime mean,” “mean time meaning”
Alternatives intent: “another word for in the meantime,” “meantime synonym”
Technical intent: “Greenwich Mean Time,” “mean solar time,” “MTBF”
Example intent: “meantime in a sentence,” “mean time examples”

Matching your answer to the reader’s intent is what makes a page useful, whether you’re writing for search or for a colleague.

Common Mistakes With “Meantime” and “Mean Time”

Here is a quick before-and-after table to keep handy.

❌ Incorrect	✅ Correct	Why
In the mean time, please wait.	In the meantime, please wait.	You mean a waiting period.
The call is at 5 p.m. Greenwich Meantime.	The call is at 5 p.m. Greenwich Mean Time.	GMT is a fixed technical term.
Our system’s meantime between failures is low.	Our system’s mean time between failures is low.	It’s an average measurement.
For the mean time, use the old form.	For the meantime, use the old form.	A waiting period again.

Case Study: One Space, One Mistake

Workplace Email Example

Imagine a project manager sends this to a client:

“The design team is revising the proposal. In the mean time, please send over the brand guidelines.”

The client understands, but a careful reader may notice the error and quietly lose a little confidence. Now look at the fixed version:

“The design team is revising the proposal. In the meantime, please send over the brand guidelines.”

Nothing else changed, just one missing space. In professional writing, small details like this shape how polished you appear, so they’re worth a few seconds of checking.

Reference Cambridge Dictionary Definitions

The Cambridge Dictionary describes “in the meantime” as the period between two events, or while something else is going on. That matches what we’ve covered: it’s a time-gap phrase built on the one-word noun “meantime.”

For “mean time,” Cambridge and similar dictionaries treat it under the technical sense of average or standardized time, as in mean solar time. For the exact current wording, check the Cambridge Dictionary directly, since entries are updated from time to time.

FAQs

What does “meantime” mean?

“Meantime” means the period between now and a future event, or the time while something else is happening. It’s most often used in “in the meantime.”

What does “mean time” mean?

“Mean time” (two words) is a technical term for average or standardized time, such as Greenwich Mean Time or mean time between failures.

Is “in the meantime” correct?

Yes. It’s the standard, widely accepted spelling for “while we wait” or “during the interval.”

Is “in the mean time” grammatically correct?

Not in modern usage. It appears in older texts, but current style guidance prefers the one-word “meantime.”

What is another way to say “in the meantime”?

Use “meanwhile,” “for now,” “for the time being,” “in the interim,” or “until then.”

Conclusion

The rule is simple: “meantime” is for waiting, “mean time” is for measuring. If you’re describing what happens between two events, write it as one word. If you’re naming a time standard or an average, write it as two.

Run the swap test with “meanwhile” when you’re unsure, and don’t rely on spellcheck to catch the error. Get this one small habit right and your emails, reports, and articles will read as more polished.