casus belli

[key-suh s bel-ahy, bel-ee; Latin kah-soo s bel-lee]

See more synonyms for casus belli on Thesaurus.com

noun, plural ca·sus bel·li

[key-suh s bel-ahy, bel-ee; Latin kah-soos bel-lee] /ˈkeɪ səs ˈbɛl aɪ, ˈbɛl i; Latin ˈkɑ sus ˈbɛl li/.

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

Origin of casus belli

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for casus belli

harassment, indignity, affront, insult, grievance, motivation, justification, annoyance, taunt, challenge, incentive, instigation, reason, dare, offense, injury, cause, vexation, inducement, grounds

British Dictionary definitions for casus belli

casus belli

noun plural casus belli (ˈkɑːsʊs ˈbɛliː)

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

Word Origin for casus belli

literally: occasion of war

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for casus belli

1849, from Latin casus "case" (see case (n.1)) + belli, genitive of bellum "war" (see bellicose). An act justifying war.