Mexican X Part I: Why Is México Pronounced Méjico?

Over the years, I’ve come across the same question again and again, always some variation on the following:

“Why is Mexico spelled ‘México’ in Spanish, especially if in Nahuatl Mēxihco was pronounced [meshiko]? What’s up with that ‘x’?”

The answers given are usually partially right or totally wrong.

Guess what? I’m going to explain it to you.

Quick note on representing sounds. If I put something in brackets [like this], it’s because I’m representing a sound with a…