คำว่า ' countersign ' ( VT )
มีความหมายในภาษาไทยว่า ลงนามร่วม
คำนิยามในภาษาอังกฤษ (definition) :
[v. t.] To sign on the opposite side of (an instrument or writing); hence, to sign in addition to the signature of a principal or superior, in order to attest the authenticity of a writing.
[a.] The signature of a secretary or other officer to a writing signed by a principal or superior, to attest its authenticity.
[a.] A private signal, word, or phrase, which must be given in order to pass a sentry; a watchword.