What was Egypt known as and why?

According to Strong's:
Egypt - in Hebrew, Mizraim, land of Egypt, or Koft or Coft; and may be interpreted hollow land, or land of depression, or hidden land. The Copts called it Elkibit, inundated land; and this idea is in all the kindred roots. It was also called Mizraim, two - fold depression, and also the land of Ham, and Khemi, black land.