Kathenotheism is a term coined by the philologist Max Müller to mean the worship of one god at a time. It is closely related to henotheism, the worship of one god while not rejecting the existence of other gods. Müller coined the term in reference to the Vedas, where he explained each deity is treated as supreme in turn.
The ancient Orphic religion has a theology comparable to kathenotheism. The Orphic Hymns address each god of the Olympian pantheon as supreme in turn.
The Smarta Tradition of Hinduism worship the five major deities as supreme in turn and collectively.