Monotheism definition is - the doctrine or belief that there is but one god.
Monotheism comes from the combination of the greek prefixes monos-, alone or single, and theo-, god. There are many words that come from the greek base theo- theology, polytheist, and atheism, to name a few.
monotheism | Definition, Types, Examples, & Facts | Britanni
Monotheism, belief in the existence of one god, or in the oneness of god. As such, it is distinguished from polytheism, the belief in the existence of many gods, from atheism, the belief that there is no god, and from agnosticism, the belief that the existence or nonexistence of a god or of gods is unknown or unknowable.