- (a.) A private signal, word or phrase, which must be given in order to pass a sentry; a watchword.
- (a.) The signature of a secretary or other officer to a writing signed by a principal or superior, to attest its authenticity.
- (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.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). countersign. Retrieved September 20, 2026, from http://smartdefine.org/countersign/definitions/1992283 |
| Chicago | Webster's. 2011. "countersign" http://smartdefine.org/countersign/definitions/1992283 (accessed September 20, 2026). |
| Harvard | Webster's 2011, countersign, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/countersign/definitions/1992283>. |
| MLA | Webster's. "countersign" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/countersign/definitions/1992283> |