/ˈkaʊntəsaɪn/ – verb
Definition: ký áp, ký xác nhận, ký duyệt.
A more thorough explanation: In legal terms, the word “countersign” refers to the act of signing a document as a witness to verify its authenticity or to confirm that the document has been reviewed and approved. This additional signature serves as a form of authentication or endorsement of the document.
Example: The contract requires both parties to countersign the agreement for it to be considered valid.