What is "countersigns"

Usage examples of "countersigns".

I knew the signs and countersigns for entry into the stronghold through the sea gate.

We had, after all, known the signs and countersigns, and, presumably, those of the holding of Policrates would not be familiar with all of the men or ships of Ragnar Voskjard.

I said, "it was you yourself who gave to me the signs and countersigns, when I posed as the courier of Ragnar Voskjard.

More importantly, she would doubtless be carrying papers linking her with Policrates, such papers as the signs and countersigns whereby the actions of the joint pirate fleets might be integrated and directed.

I'll com back within forty-five minutes with final instructions and the challenges and countersigns you'll need.

On the other hand, whatever might have been the contents of the sealed leather cylinder delivered into this hands with signs and countersigns I did not know.

He had discussed the need for signs and countersigns at night with Zechariah but apparently he hadn't been very clear.

After a nervous pause while they exchanged codes and countersigns, they locked onto a docking hatch.