casus belli
Preserved but no longer current.
Meaning · English
(Lat.). A ground for war; an occurrence warranting inter- national hostilities.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “casus belli” mean?
(Lat.). A ground for war; an occurrence warranting inter- national hostilities.
Is “casus belli” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.