The Collaborative International Dictionary
Henotheism \Hen"o*the*ism\, n. [Gr. e"i`s, "enos`, one + E. theism.] Primitive religion in which each of several divinities is regarded as independent, and is worshiped without reference to the rest. [R.]
Douglas Harper's Etymology Dictionary
1860, from Greek henos, neuter of eis "one" (from PIE *sem- "one, as one") + theism. Devotion to a single god without asserting that he is the only god. Coined by (Friedrich) Max Müller (1823-1900), professor of comparative philology at Oxford. Related: Henotheist.
Wiktionary
n. Belief in or worship of one deity without denying the existence of other deities.
Wikipedia
Henotheism ( Greek henas theos "one god") is the belief in and worship of a single god while accepting the existence or possible existence of other deities. The term was originally coined by Friedrich Schelling (1775–1854), and used by Friedrich Welcker to depict primordial monotheism among ancient Greeks.
Max Müller (1823–1900), a German philologist and orientalist, brought the term into wider usage, in his scholarship on the Indian religions. Müller made the term central to his criticism of Western theological and religious exceptionalism (relative to Eastern religions), focusing on a cultural dogma which held "monotheism" to be both fundamentally well defined and inherently superior to differing conceptions of God.