Where does “索引” come from?

索引 (Japanese) comes from Japanese 引, from Middle Chinese 引.

索引 (Japanese): index, indices, indexes

Definitions

  1. index, indices, indexes

Ancestry of “索引”, step by step

索引 traces back through two separate lines of ancestry.

via Japanese 引

StepLanguageWordMeaning
1Japanese引the preface to a book; introduction; foreword
2Middle Chinese引—

via Japanese 索

StepLanguageWordMeaning
1Japanese索—
Every word from Middle Chinese 引 →Every word from Japanese 引 →