Definition Of countersign
a signal or password given in reply to a soldier on guard.
If two soldiers have the day's password and countersign , they can get physically close enough to kill each other without knowing that their uniforms don't match or their language isn't even the same.
add a signature to (a document already signed by another person).
each check had to be signed and countersigned
Example Of countersign
A record in the resident's money book showed the details of the money transferred into this account from their personal account for the purchases, and ‘this is signed by the resident and countersigned by the nursing officer in charge’.
advance, patrol, and give the countersign to me
All have many years of training and experience and no decision can be made without the countersignature of a senior colleague.
All issuances from the emperor had to have the countersignature of the minister responsible for the area affected.
Finally, we signed and countersigned a declaration that under no circumstances would we dive deeper than 6m, nor deviate from the officially designated route as indicated by the phosphorescent orange guide ropes.