Not yet available for sale; a product that has not been released on the market.
このスマホはまだ未発売で、詳細なスペックは発表されていない。
This smartphone is not yet on sale; its detailed specs haven't been announced.
未発売のため試用はできませんが、来月から店頭に並ぶ予定です。
Because it's not yet available, you can't try it, but it's scheduled to appear in stores next month.
ネットで未発売の情報が出回っているが、公式発表を待ったほうがいい。
There are rumors online about it not being released yet, but it's better to wait for the official announcement.