Endeavor and endeavour have the same meaning: a serious effort or attempt. “Endeavor” is the American spelling, while “endeavour” is the British spelling.
Endeavor or endeavour—which one is correct? The answer is simpler than it first appears. Both spellings are correct, and neither changes the meaning of the word. The only real difference is the variety of English being used. Endeavor is the standard spelling in American English, while endeavour is preferred in British English and other varieties that generally follow British spelling conventions.
Both forms can be used as a noun or a verb. As a noun, endeavor/endeavour refers to a serious effort or attempt. As a verb, it means to make a determined effort to achieve something. For example, an American writer might say, “We will endeavor to improve our service,” while a British writer may write, “We will endeavour to improve our service.” The meaning stays exactly the same—the spelling simply follows the writer’s chosen form of English.
That extra “u” may look like a tiny detail, but it can matter in academic writing, professional communication, school assignments, websites, and other formal content. Using one spelling consistently helps your writing match your intended audience and English variety.
So, should you write endeavor or endeavour? If you’re following American English, choose endeavor. If you’re following British English, choose endeavour. Once you know this simple distinction, there is no need to second-guess the spelling again.
In this complete guide, you’ll learn the meaning, pronunciation, noun and verb forms, American vs. British usage, clear example sentences, common mistakes, and practical tips for choosing endeavor or endeavour confidently and consistently.
Endeavor or Endeavour meanings
Endeavor and endeavour are both correct spellings.
- Endeavor → American English
- Endeavour → British English
- Endeavour → Also common in British-influenced varieties such as Australian and Canadian English
Both words mean a serious effort or attempt to do something.
Examples
American English:
She made every endeavor to finish the project.
British English:
She made every endeavour to finish the project.
The meaning does not change. Only the spelling changes.
As a verb, the difference remains:
- We will endeavor to help you. — US
- We will endeavour to help you. — UK
So, if you are writing for a US audience, use endeavor. For a UK audience, use endeavour.
The Origin of Endeavor or Endeavour
The word endeavor comes from older forms of English and French. It developed from the idea of putting effort into something.
The word is related to the Old French expression mettre en devoir, which carried the sense of putting oneself under an obligation or making an effort.
Over time, English speakers shortened and changed the expression. The modern word became endeavour in British English.
American English later developed its own spelling preferences. Many words that contain -our in British English use -or in American English.
For example:
| British English | American English |
|---|---|
| endeavour | endeavor |
| colour | color |
| honour | honor |
| labour | labor |
| favour | favor |
This is why endeavour and endeavor exist today.
The spelling difference does not create a difference in meaning. It is mainly a regional spelling difference.
British English vs American English Spelling
The main difference is the ending.
British English usually keeps -our, while American English often uses -or.
Simple Rule
British English: endeavour
American English: endeavor
Here are some examples:
| Meaning | British English | American English |
|---|---|---|
| A serious effort | endeavour | endeavor |
| To make an effort | endeavour | endeavor |
| A difficult attempt | an endeavour | an endeavor |
| Future effort | future endeavour | future endeavor |
| Professional effort | professional endeavour | professional endeavor |
The same pattern appears in several other words:
| British | American |
|---|---|
| colour | color |
| honour | honor |
| behaviour | behavior |
| neighbour | neighbor |
| favour | favor |
However, not every word ending in -our changes to -or in American English. Some words have different histories and must be learned separately.
The key point is simple: endeavour is the British spelling, while endeavor is the American spelling.
Which Spelling Should You Use?
Your audience should decide which spelling you use.
For a US Audience
Use endeavor.
Example:
We will endeavor to provide better service.
This spelling is standard in American English.
For a UK Audience
Use endeavour.
Example:
We will endeavour to provide better service.
This spelling fits British English.
For Commonwealth English
Endeavour is generally used in British-influenced English varieties.
This includes many contexts in:
- Australia
- New Zealand
- India
- South Africa
- Other regions influenced by British English
For a Global Audience
Either spelling can work, but consistency matters most.
If your website uses American spelling throughout, choose endeavor. If your content follows British English, use endeavour.
Do not switch between the two spellings randomly in the same piece of writing.
Common Mistakes with Endeavor or Endeavour
Many mistakes happen because writers are unsure which regional spelling they need.
Mistake 1: Mixing Both Spellings
Incorrect style:
We will endeavor to improve our service and make every endeavour to help customers.
There is no meaning problem here, but the spelling is inconsistent if you are following one variety of English.
Better:
We will endeavor to improve our service and make every endeavor to help customers.
Or:
We will endeavour to improve our service and make every endeavour to help customers.
Mistake 2: Thinking One Spelling Is Wrong
Neither spelling is wrong.
Endeavor is correct in American English.
Endeavour is correct in British English.
Mistake 3: Using British Spelling in US Content
If your content is written in American English, endeavor is usually the better choice.
Mistake 4: Using American Spelling in UK Content
For British English writing, use endeavour.
Mistake 5: Changing the Meaning
Both words have the same meaning. The extra u does not change the definition.
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Endeavor or Endeavour in Everyday Examples
The word can appear in many types of writing.
In Emails
US:
We will endeavor to respond within two business days.
UK:
We will endeavour to respond within two business days.
In News Writing
US:
The team will endeavor to reach an agreement.
UK:
The team will endeavour to reach an agreement.
On Social Media
A casual post might say:
Every great endeavor starts with one small step.
A British writer may use:
Every great endeavour starts with one small step.
In Formal Writing
US:
The company will endeavor to meet all customer needs.
UK:
The company will endeavour to meet all customer needs.
As a Noun
Starting a new business was a challenging endeavor.
Or:
Starting a new business was a challenging endeavour.
As a Verb
We endeavor to provide useful information.
Or:
We endeavour to provide useful information.
Endeavor or Endeavour – Google Trends & Usage Data
Search interest for endeavor and endeavour varies by country because English spelling differs across regions.
In general:
- Endeavor is more common in the United States.
- Endeavour is more common in the United Kingdom.
- Endeavour is also widely used in countries that follow British English.
- Searches can change based on education, location, writing style, and the type of content people read.
The word also appears more often in formal writing than in casual conversation. People may use simpler words such as effort, attempt, or try in everyday speech.
Searches for endeavor or endeavour often come from people checking spelling before writing an email, article, school assignment, business document, or professional message.
Endeavor vs Endeavour: Side-by-Side
| Feature | Endeavor | Endeavour |
|---|---|---|
| Meaning | Serious effort or attempt | Serious effort or attempt |
| Main usage | American English | British English |
| Spelling | -or | -our |
| Verb form | endeavor | endeavour |
| Noun form | endeavor | endeavour |
| US writing | Preferred | Less common |
| UK writing | Less common | Preferred |
| Formal writing | Yes | Yes |
The most important rule is to match the spelling to your chosen variety of English.
FAQs About Endeavor or Endeavour
1. Is endeavor or endeavour correct?
Both are correct. Endeavor is the American spelling, while endeavour is the British spelling.
2. Is endeavor American or British?
Endeavor is mainly the American English spelling.
3. Is endeavour British spelling?
Yes. Endeavour is the standard British English spelling.
4. Do endeavor and endeavour mean the same thing?
Yes. Both mean a serious effort or attempt to achieve something.
5. Can I use endeavour in American English?
You can, but endeavor is the usual American spelling. Using endeavour may make the writing look influenced by British English.
6. Which spelling should I use for a UK website?
Use endeavour if your website follows British English spelling.
7. Which spelling is best for a US website?
Use endeavor if your website follows American English. The main goal is to keep your spelling consistent.
Conclusion
The choice between endeavor or endeavour is simple once you know the regional difference. Both words are correct, and both have exactly the same basic meaning: a serious effort or attempt.
The main difference is spelling. Endeavor is the standard American English form, while endeavour is the standard British English form. The British spelling is also common in many countries and writing systems influenced by British English.
When choosing between them, think about your readers first. If you write for people in the United States, endeavor is the natural choice. If you write for a UK or British-English audience, choose endeavour.
There is no need to treat one spelling as more correct than the other. What matters most is using the form that matches your chosen style of English and keeping that spelling consistent throughout your writing. Once you follow this simple rule, the endeavor vs endeavour confusion becomes easy to solve.
Elizabeth Bowen is a creative writer at funcaptionz.com, sharing thoughtful English captions, short content, and inspiring ideas for modern readers.
