Lord / Nobility / Monarch
Originally, the term referred to the Son of Heaven, dukes or princes, ministers, and senior officials who owned land and ruled the common people. It later referred to ducal monarchs and the emperor only. The Chinese character 君 is composed of two parts, namely, 尹 and 口. The top part 尹 means to run a country and govern its people, and the lower part 口 means to give orders. Ancient Chinese believed that a monarch or nobility must possess four qualities: first, having extraordinary virtues and be competent; second, having the mandate of Heaven; third, in possession of land or manor; and fourth, having the ability to govern officials and common people, and enjoying their unfailing loyalty.
The Son of Heaven, dukes or princes, ministers, and senior officials who own land are all regarded as the nobility or lord. (Zheng Xuan: Annotations on The Book of Rites and Rituals)
The lord, monarch or nobility rules over common people who pledge loyalty to their authority. (Debates of the White Tiger Hall)