A hidden or treasured item — something valuable that is carefully kept or concealed; often used for historically or culturally precious objects.
寺の庫裏から古い秘宝が見つかったというニュースが流れた。
News came out that an old treasure had been discovered in the temple's storehouse.
博物館では国の秘宝が特別展示されている。
The museum is exhibiting the country's treasured artifacts in a special display.
彼女はその指輪を秘宝のように大切にしている。
She cherishes that ring as if it were a treasured heirloom.