A physical property, such as weight or temperature, that can be observed or measured directly, as distinguished from a quantity, such as work or entropy, that must be derived from observed quantities.

• 可遵守的一项物理特性，能直接观察或测量到，如重或温度，而不象功或熵等这一类，这些必须从所观测到的各种不同的量推算出来