A constitutional amendment to do what? Article II does not define natural-born citizen.
The constitution does not define High Crimes and Misdemeanors either, but it has not stopped officials from being impeached. That is the purpose of precedent, stare decisis, textual analysis, and research into original intent.
The constitution was never intended to be a dictionary.
The second amendment does not define “shall not be infringed”, it is still clear to clear-thinking people.
The only ones who don’t understand both phrases are the ones who don’t want to.