WATCHMAN נֹצֵ֥ר, careful watcher; צֹּפֶה, outlooker; שֹׁמֵ֥ר, one who guards; מְצַפֶּ֔ה, watchman. One whose duty it is to guard or watch a city or a harvest field, esp. at night.
Watchmen kept watch over fields and vineyards during the time of harvest. Sometimes whole families would act as watchmen; to protect themselves from the heat, they frequently erected simple booths, and to facilitate observation they built watchtowers (2 Kings 17:9; 2 Chron 20:24; Job 27:18).
Prophets in the OT are described as being watchmen of God, announcing to the people of Israel impending doom from Jehovah or bringing good news to them (Isa 21:6; 52:8; 62:6; Jer 6:17; Ezek 3:17). The solemn responsibility of the prophets of Israel to the nation is described in Ezekiel 33:2-6. False prophets are blind watchmen (Isa 56:10).
The word is not found in the NT.