ISIS (Ίσις).  Greek rendering of Coptic Esi (Hesi), meaning "ancient."  In Egyptian mythology, this is the name of a goddess of the moon.

... The name "Isis" means "ancient," and has been applied to the moon from time immemorial.  Osiris and Isis govern the whole world, and they foster and protect everything in it,... (Osiris and the Egyptian Resurrection, Budge, v.1, 1911)

    ISIS, a queen of Egypt, of the Older Empire.  Her tomb was broken open by robbers in the reign of Rameses IX.
    Isis, a great Egyptian goddess, the second member of the second great triad, Osiris, Isis, and Horus.  She was the queen and the personification of heaven, and the sister and wife of Osiris, whose members she sought throughout Egypt to collect and bury, when he was slain, and his limbs scattered, by his brother Set.  She was generally represented as a beautiful woman, with full breasts and winged arms, and wearing a throne on her head; the throne, hesi, being the Hieroglyphic of her name.  Isis was also often represented as wearing a disk between two cow's horns, and under that form she was almost always confounded with the goddess Hathor, while in the most ancient monuments of Egypt the cow was also her symbol.  Sometimes again Isis was figured as standing upright, and with her arms, which were furnished with wings, covering the mummy of Osiris, or occasionally enfolding the statue of the king; and in that characteristic she was called "Isis the Protectress;" since she was thus supposed to be bringing the dead body of her husband to life.  Sometimes, also, the goddess was figured as holding her hand upwards before her face, as in a posture of grief, during which position she was believed to pronounce the mystical evocations to the soul of Osiris.  Astronomically, the spirit of Isis was placed in the star Sirius, which under the name of Sothis held an important position in the astrological and astronomical calendar of the Egyptians.  See also Hathor, Osiris, and Horus.
    Isis, the sister of Har-s-ankh, an Egyptian gentleman of rank in the XIIth dynasty. (An Archaic Dictionary, Cooper, 1876).