Endeavour vs. Endeavor
The difference is regional spelling, not meaning. Use “endeavour” in UK-oriented spelling and “endeavor” in US-oriented spelling, then stay consistent with the document’s variety of English.
“Endeavour” is the usual British spelling; “endeavor” is the usual US spelling. The noun and verb meanings are the same in this comparison.
Key details
Choose the right form
| Meaning / context | Use | Decision |
|---|---|---|
| UK-oriented spelling | endeavour | Use the British form. |
| US-oriented spelling | endeavor | Use the American form. |
| meaning or grammatical role | no difference created by the spelling choice | Both forms can function as noun or verb in the same senses. |
Quick tests
Decision test
Is the document following British spelling conventions?
If yes: Use “endeavour.”
If no: Use “endeavor” for US-oriented spelling.
Caveat: Treat this as a regional spelling preference, not a correctness or meaning difference.
Examples
The team will endeavour to finish before Friday.
The sentence follows British spelling.
The team will endeavor to finish before Friday.
The sentence follows US spelling.
The research endeavor lasted several years.
The US spelling works as a noun as well as a verb.
Further guidance
Core difference
Use the British form.
Fast Test
Use “endeavour.” Use “endeavor” for US-oriented spelling.
Usage Boundary
Treat this as a regional spelling preference, not a correctness or meaning difference.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- endeavour (opens in a new tab)Cambridge University Press · Endeavour is the UK spelling of the noun/verb meaning an attempt or to try, with US counterpart endeavor.
- endeavor (opens in a new tab)Cambridge University Press · Endeavor is identified as the US spelling of endeavour.