Countersign

Part of speech: verb, noun

Definitions

1. To provide a secondary signature in confirmation; to give an additional approving sign; the signature used to validate or confirm a previous signature
2. To endorse or authenticate by signing again; to supply a corroborative mark; the act or mark of validating a prior autograph or order
3. To add a confirming signature; to give a countermark as approval; a signature that serves to verify or sanction an earlier signature or directive

Etymology: The word "countersign" joins "counter-" to "sign," and its earliest form came into English through Middle French, where "contresigne" carried the sense of a secret watchword or signal. Its original job was military and secretive: a password given out so that a guard could tell a friend from an enemy, with the countersign being the reply that confirmed the right person had spoken. From there the meaning moved toward official paperwork. A countersign came to mean a second signature added beside an original one, so that a document was validated by two hands rather than one. That is the sense still in use when a secretary or official adds a mark beneath a superior's autograph to certify it. The verb followed the noun, so to countersign a document is to add that corroborating mark.

Synonyms: authenticate, endorse, confirm, validate, approve

Antonyms: invalidate, deny, reject, disapprove