Cách sử dụng
The word 'sentinel' refers to a person or thing that is placed to guard or watch over something. It could be a soldier standing guard at a gate, a security camera monitoring a building, or even a pet dog keeping watch over its owner's property. Sentinel is often used in military and security contexts, but can also be used metaphorically to refer to something that serves as a protector or guardian of a particular thing or idea.