Where does “インド洋” come from?

インド洋 (Japanese) comes from Japanese インド, from Chinese 印度.

Ancestry of “インド洋”, step by step

インド洋 traces back through two separate lines of ancestry.

via Japanese インド

StepLanguageWordMeaning
1JapaneseインドIndia
2Chinese印度

via Japanese

StepLanguageWordMeaning
1Japanesean ocean; the East or "especially" the West;...
2Middle Chinese
Every word from Chinese 印度Every word from Japanese インド