The act of returning something borrowed or held to its owner or original place; commonly used for returning library books, rentals, etc.
図書は期限までに返却してください。
Please return library books by the due date.
レンタカーは営業所に返却した。
I returned the rental car to the office.
商品が不良品だったため、業者に箱ごと返却した。
Because the product was defective, I returned it (the box and contents) to the company.