> Although there is also no definition of "common usage".. am I missing something
Common usage is defined in the article as the widespread name used by the local people to refer to it.
The moment the president of the US renamed those bodies of water, it became commonly used in all sort of publications since then. It fits their description, no matter how silly.
The moment the president of the US renamed those bodies of water, it became commonly used in all sort of publications since then. It fits their description, no matter how silly.