under seal

Bearing a seal. / (law) Legally bound not to be disclosed.

Japanese Meaning

印章によって封印された状態 / 法的に秘密保持義務がある状態

The document, under seal, was presented to the court as proof of ownership.

その文書は印が押されており、所有権の証拠として裁判所に提出された。

Sense（1）

Bearing a seal.

The letter was delivered under seal.

Sense（2）

(law) Legally bound not to be disclosed.

The terms of the settlement will remain under seal indefinitely.