| noun | a secret word or phrase known only to a restricted group “he forgot the password” |
| noun | a second confirming signature endorsing a document already signed |
| verb | add one's signature to after another's to attest authenticity “You must countersign on this line of the contract” |
| countersign | verb | add one's signature to after another's to attest authenticity |
| countersign | noun | a second confirming signature endorsing a document already signed |
| countersignature | noun | a second confirming signature endorsing a document already signed |