Denshi Jisho — Online Japanese dictionary

慣習 かんしゅう usual (historical) custom
Common word, Noun, Suru verb, No-adjective 
慣習 かんしゅうほう 1: common law;
2: customary law (in international law)
Noun 
慣習国際法 かんしゅうこくさいほう customary international law
Noun 

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