This is the 725th most frequent Chinese word.
忠诚
Loyalty; faithfulness.
Here, '忠诚' is used as an adjective to describe a friend's characteristic of being faithful and reliable.
作为一名忠诚的朋友，他总是在我需要的时候帮助我。
As a loyal friend, he is always there to help me when I need it.
In this sentence, '忠诚' signifies a value or principle, demonstrating its abstract and philosophical use.
我们要以忠诚作为我们的生命原则之一。
We must consider loyalty as one of the principles of our lives.
This sentence illustrates the use of '忠诚' (loyalty) as a noun, referring to a person's devotion or faithfulness to a cause or duty.