seal
/sil/
fastener consisting of a resinous composition that is plastic when warm; used for sealing documents and parcels and letters
中文释义:封条;印章
The document was secured with a wax seal to prevent tampering.
文件用蜡封封好以防篡改。
He broke the seal of the envelope and read the letter inside.
他撕开信封的封口,读了里面的信。