‘卫士’ literally combines 卫 (wèi), meaning ‘to guard’ or ‘to defend’, and 士 (shì), meaning ‘scholar’, ‘gentleman’, or ‘person of high status or duty’. Together, they form a compound noun meaning ‘guard’ or ‘bodyguard’—a person entrusted with protecting someone important, such as a VIP, official, or royal figure. It carries a formal, respectful connotation and is often used in official, historical, or ceremonial contexts.

The term implies loyalty, vigilance, and disciplined service. While it can refer to modern security personnel, it’s more commonly found in literature, news reports about state protection, or descriptions of palace guards in historical dramas. Unlike the more generic 保安 (bǎo'ān, ‘security guard’), 卫士 suggests higher rank, specialized training, and closer proximity to the person being protected. It may also appear metaphorically—for example, describing environmental activists as ‘guardians of nature’—though this usage is less common and usually marked by context or modifiers.