noun
extranet
A private network that uses internet technology to share part of an organization's information with external partners, suppliers, or customers. Contrasts with the public Internet.
取引先と情報を共有するためにエクストラネットを構築した。
We built an extranet to share information with our business partners.
Variant with interpunct; less common but still seen.
Borrowed from English 'extranet', a blend of 'extra' and 'network'.