君 is a classical noun with two main branches of meaning in modern Chinese. The first is 'monarch' or 'sovereign', used in historical and political terms like 君主 (monarch) and 国君 (sovereign of a state). The second is a formal, respectful term of address: attached after a surname (e.g., 张君, 李君) it functions like 'Mr.' in written Chinese, especially in letters and official announcements. It also appears in the core Confucian term 君子 (jūnzǐ, 'gentleman' or 'person of virtue'). 君 is rarely used alone in everyday speech; its meaning is nearly always carried by compounds or fixed phrases.