Casus /(?)/

Ca·sus

Casus

n.
  1. An event; an occurrence; an occasion; a combination of circumstances; a case; an act of God. See the Note under Accident.

Phrases & Compounds
Casus belli
an event or combination of events which is a cause war, or may be alleged as a justification of war.
Casus fortuitus
an accident against which due prudence could not have provided. See Act of God, under Act.
Casus omissus
a case not provided for by the statute.