What is another word for counter-sign?
Pronunciation: [kˈa͡ʊntəsˈa͡ɪn] (IPA) 
Counter-sign is a term used to refer to the act of signing a document or a piece of writing already signed by someone else, in order to confirm the authenticity of the signature. Synonyms for this term include countersignature, co-sign, co-signature, and witness signature. These terms are commonly used in legal documents, contracts, and official paperwork of various kinds. Other related terms that can be used interchangeably with countersign include validation, authentication, certification, and endorsement. In essence, countersign is a crucial element required in many scenarios to ensure the validity and legitimacy of a signature.
