Kathenotheism is a term coined by the philologist

Philology

Philology is the study of language in written historical sources; it is a combination of literary studies, history and linguistics.Classical philology is the philology of Greek and Classical Latin...

 Max Müller

Max Müller

Friedrich Max Müller , more regularly known as Max Müller, was a German philologist and Orientalist, one of the founders of the western academic field of Indian studies and the discipline of comparative religion...

 to mean the worship of one god

God

God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....

 at a time. It is closely related to henotheism

Henotheism

Henotheism is the belief and worship of a single god while accepting the existence or possible existence of other deities...

. Müller coined the term in reference to the Vedas

Vedas

The Vedas are a large body of texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism....

; where he explained each deity is treated as supreme in turn.

Etymology

The term kathenotheism is a more specific form of the parent term henotheism

Henotheism

Henotheism is the belief and worship of a single god while accepting the existence or possible existence of other deities...

, and refers to the worship of a succession of supreme gods "one at a time," from the Greek kath' hena "one by one" + theism.

Ancient Greece

The ancient Orphic religion has a theology comparable to kathenotheism. The Orphic Hymns address each God of the Olympian pantheon as supreme in turn.