Cambridge labels “rancour” as UK formal and “rancor” as US formal for the same noun. This guide treats the choice as a documented spelling convention and does not invent a meaning difference between the variants.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Use “rancor” in standard US spelling and “rancour” in standard UK spelling; both refer to the same core idea of continuing bitter anger.
Key details
Confusion Familyregional-variant
Rule Familyregional-usage
TermsRancor, Rancour
Variant ScopeCambridge labels “rancour” as UK formal and “rancor” as US formal for the same noun.
Further guidance
Core difference
Use “rancor” in standard US spelling and “rancour” in standard UK spelling; both refer to the same core idea of continuing bitter anger.
Style Boundary
Choose the spelling that matches the audience, region, or house style, and keep that choice consistent where both forms are accepted.
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.
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