monolatry

Etymology
From.

Noun

 * 1) A belief system with one god who can take on multiple faces (the One and the Many). Coined by Egyptologist Erik Hornung in his book Conceptions of God in Ancient Egypt: The One and the Many to characterise Kemetic religions (northern Egypt; Nile delta).
 * 2) The worship of a single deity (possibly while believing in the existence of others).

Translations

 * Japanese: 拝一神教, 一神崇拝
 * Swedish: monolatri