The crossword solution for the term 'Wife/Sister of Osiris' is ISIS, which is a four-letter word. Isis was an ancient Egyptian goddess who was the wife and sister of Osiris, the god of the afterlife, the underworld, and rebirth. She was also known as the goddess of magic, healing, and protection. She was one of the most important and popular deities in ancient Egypt and was worshiped by many people.