"worship of strange gods," 1650s, from allo- "other" + -theism.
Entries linking to allotheism
allo-
word-forming element meaning "other," from Greek allos "other, different," cognate with Latin alius "other," from PIE root *al- (1) "beyond."
-theism
word-forming element meaning "belief (of a specified kind) in God, a god, or gods," from Greek theos "god" (from PIE root *dhes-, forming words for religious concepts) + -ism.