Watchman— Someone given the responsibility to guard or to warn others.
God had assigned Ezekiel as the watchman to Israel. It was his responsibility to warn Israel of the danger to come.
Many of the prophets of God were watchman. They foretold the outcome of the actions of the people.
In the world today the first and by far the most important responsibility of every Christian is to warn the world of the and time. Day after day goes by and most do not believe God will punish anyone or that He even exist.
Mark 16:15-16 “…Go into all the world and preach the gospel to every creature. He who believes and is baptized will be saved; but he who does not believe will be condemned