noun
customary international law
A technical term in international law referring to unwritten rules derived from consistent state practice and opinio juris.
慣習国際法は、国家間の長年の慣行から生まれる。
Customary international law arises from long-standing practices among states.
Treaty law is written and explicitly agreed upon, while customary international law is unwritten and based on practice.
Compound of 慣習 (custom, practice) and 国際法 (international law).