back order
A business term for an order that cannot be filled immediately and is placed on back order.
その商品は現在バックオーダーとなっております。
That item is currently on back order.
取り寄せ refers to ordering an item for a customer, while バックオーダー specifically means the item is out of stock and the order is pending.
Variant with interpunct; less common in running text.
Loanword from English 'back order'.