According to Wikipedia, the title "Pharaoh" is a New Kingdom one:
Pharaoh is the common title of the monarchs of ancient Egypt from the First Dynasty (c. 3150 BCE) until the Macedonian conquest in 305 BCE, although the actual term "Pharaoh" was not used contemporaneously for a ruler until circa 1200 BCE.
Pharaoh. (2017, March 15). In Wikipedia, The Free Encyclopedia. Retrieved 13:25, March 16, 2017, from https://en.wikipedia.org/w/index.php?title=Pharaoh&oldid=770486002
What title did the Egyptians use for their rulers before the title "Pharaoh" came into use?