casus foederis

/ˌkeɪ.səs ˈfiː.də.ɹɪs/

keɪ · SƏS FIː · də · ɹɪs (4 syllables)

English Noun

Definition

A situation covered by the terms of an international treaty (or similar understanding), and which consequently requires action from the parties involved.

Etymology

From Latin casus (“case”) + foederis, genitive of foedus (“treaty”).