Why is the word silent composed of black and dog?

Let me tell you! Represents silence! Erlang Shen's dog is black. The dog that barks does not bite people, and the dog that does not bark bites people to death. Every time the Roaring Dog is trained to remain silent, but once someone threatens its owner, it bites hard and will no longer be silent. Maybe the word "silent" is to praise the black Roaring Dog? Hey, where did I go with this? I’m just kidding, haha