Pharaoh was a name for the office of kingship in the New Kingdom of ancient Egypt. Meaning "Great House", it originally referred to the king's palace, but the meaning loosened over the course of Egyptian history until it became interchangeable with the Egyptian word for king. Although the rulers of Egypt were generally male, the pharaoh was used on the rare occasions when a female ruled. Such rulers were believed to be the incarnation of Horus.The Way to Eternity: Egyptian Myth, F. Fleming & A. Lothian, 12, 59
Etymology
The term pharaoh ultimately derives from a compound word represented as pr-`3, used only in larger phrases like smr pr-`3 'Courtier of the Great House', with specific reference to the buildings of the court or palace itself.Ancient Egyptian Grammar (3rd ed.), A. Gardiner (1957-) 71-76 From the Twelfth Dynasty onward the word appears in a wish formula 'Great House, may it live, prolth', but again only with reference to the buildings and not the person.The earliest inst
Source:
http://en.wikipedia.org/wiki/Pharao