ブックストラップ

noun

book strap

A strap used to carry or secure books, often attached to a book cover or used as a bookmark with a strap.

• このブックストラップは革かわ製せいで、本ほんをしっかりと閉とじておける。

  This book strap is made of leather and keeps the book securely closed.

• 旅りょ行こう中ちゅうにブックストラップで本ほんをまとめて持もち運はこんだ。

  I carried my books together with a book strap during the trip.