A custom order; goods specially made to a customer's specification (made-to-order, bespoke).
結婚式用のドレスを特注で作ってもらった。
I had a dress made to order for the wedding.
家具は特注すると納期が長くなることが多い。
When you order custom furniture, delivery times are often longer.
この部品は市販されていないので特注で製作した。
This part isn't sold commercially, so we had it made to order.