worker who cleans streets and removes garbage

One of the eight provinces of Korea during the Joseon dynasty, now divided into South Korea's [[忠清北道|忠清北道|zhong1 qing1 bei3 dao4]] and [[忠清南道|忠清南道|zhong1 qing1 nan2 dao4]].

To explain something thoroughly until it is clear and understood; to speak clearly and plainly.