The word 清洁工 is formed by combining two meaningful parts: 清洁, which means "clean" or "to clean", and 工, which means "worker" or "laborer". It is a direct and practical compound where the first part describes the nature or purpose of the work, and the second part identifies the person who performs it. Together, they logically create the concept of a "cleaning worker" or janitor, building the idea from its core function to the person fulfilling it.