One who guards against possible harm to people or property, often during the night, and who may sound an alarm in the face of threatened danger. Watchmen were often stationed on the city walls and towers to observe those approaching before they got close. A watchman in the military is usually called a guard or a sentry. Figuratively, prophets served as watchmen to the nation of Israel, warning of impending destruction.​—2Ki 9:20; Eze 3:17.