monolatry
If you looked in your dictionary for the term monolatry and didn't find it, there's a good reason. The term has only existed for half a century, having been coined by Erich Winter and Siegfried Morenz in reference to Near Eastern conceptions of God, and applied to ancient Egypt by Erik Hornung, Jan Assmann, and other Egyptologists and students of religion. Monolatry is the belief that god (as the One) can manifest Itself into other aspects and manifestations (the Many) with Their own personalities and interactions between one another, without ever losing sight of the fact that They all spring forth from the initial One. To abbreviate it to four words: "One divine category, many gods and goddesses." The best example of this is to imagine the Nile and the branches it divides into as it nears the Delta region -- many streams, each having their own name and location, but all of them springing from one water. Monolatry is a form of polytheism, "many gods," but it also permits for a singular Godhead, so Kemetic religion as a monolatry is a modified or special form of polytheism. Sometimes monolatry is referred to as "henotheism," where one acknowledges the existence of many gods but only tends to worship Them one at a time.