It is made up of "Shahr" and "iar". "Shahr" means "state" and "iar" means "supporter or friend". This was a term that was used to address Kings a couple of thousand years ago. There are many other names made up the same way, for example: Shahrzad is made up of "Shahr" and "zad", meaning "Born in the state". "Shahrdar" means "keeper" of the state and is used for "mayor".