casus belli

[ key-suhs bel-ahy, bel-ee; Latin kah-soos bel-lee ]

noun

, plural ca·sus bel·li [key, -s, uh, s , bel, -ahy, bel, -ee, kah, -soos , bel, -lee].

1. an event or political occurrence that brings about a declaration of war.

casus belli

/ ˈkɑːsʊs ˈbɛliː /

noun

1. an event or act used to justify a war
2. the immediate cause of a quarrel

Word History and Origins

Origin of casus belli¹

1840–50; < New Latin: literally, occurrence of war

Word History and Origins

Origin of casus belli¹

literally: occasion of war

Example Sentences

Unfortunately we had no casus belli against Spain, and could not found one on secret information.

From Project Gutenberg

Here, as I have said, was the real casus belli,—a constant irritation that had at length got past bearing.

From Project Gutenberg

The Porte was persuaded not to regard the invasion of the Danube principalities as a casus belli.

From Project Gutenberg

Then, in case of such special edict, Martha Biggs should go, and thence should arise the new casus belli.

From Project Gutenberg

The casus belli was simple, but, as reported, most irritating.

From Project Gutenberg

Related Words

• affront
• harassment
• indignity
• insult