Does Mexico mean bellybutton of the moon?

The name "Mexico" does not mean "bellybutton of the moon". The word "Mexico" is derived from the Nahuatl words "metztli" (moon) and "xictli" (navel/center). It was originally the name of the Aztec capital city, Tenochtitlan, which was built on an island in the middle of Lake Texcoco. The city was considered to be the center of the Aztec world, and its name reflected this. Over time, the name "Mexico" came to be used to refer to the entire country.