watchword

A prearranged reply to a challenge, as from a guard or sentry; a password.

A rallying cry.

A word or short phrase to be communicated on challenge to the watch or sentinels in a camp; a password or signal by which friends can be known from enemies.

Hence Any preconcerted indication or a direction eagerly watched for, as a signal for action.

A word used as a motto, as expressive of a principle or rule of action; a maxim, byword, or rallying-cry.

The call of a watchman or sentry as he goes his rounds.

A word given to sentinels, and to such as have occasion to visit the guards, used as a signal by which a friend is known from an enemy, or a person who has a right to pass the watch from one who has not; a countersign; a password.

A sentiment or motto; esp., one used as a rallying cry or a signal for action.

a prearranged reply to the challenge of a sentry or a guard; a password or signal by which friends can be known from enemies

a word used as a motto, as expressive of a principle or rule of action; a maxim, byword