According to HoloWeb.net, the Egyptian cross is known as the Ankh, and it has many meanings, most notably immortality. It can also signify death and balance. Ancient Egyptians also saw it as a positive symbol that represents life.
There are several theories regarding the look of the cross and its additional meaning. According to Seiyaku.com, the Ankh is also related to a looped, cross-like symbol that represents life and fertility. Some theorists believe that the shape of the Ankh also means a union between man and woman, a merging of the genitals. In this regard, it would be seen as another fertility symbol representing vitality and sexual prowess.
Another theory holds that the loop portion of the cross is a hieroglyph that represents life and a sandal strap wrapped around an ankle. Experts believe life and a sandal's thong held the same pronunciation. Seiyaku.com also mentions that the English word "ankle" derives from the Indo-European word "ank."
Many other cultures adopted the Ankh, including early Christians who saw it as the cross of their faith, and it also means the Tree of Life. For other cultures, the loop portion of the cross means the sun. It also represents Atum, a god who is associated with the sun. It was also seen by the Ancient Egyptians as a key that unlocked the Kingdom of the Dead. The loop can also symbolize an eternal circle representing the soul, with no beginning or end.