False god
In some monotheistic religious denominations, the deities of pagan religions -- as well as other competing entities or objects to which particular importance is attributed -- are often called false gods. Conversely, polytheistic pagans may regard the gods of various monotheistic religions as "false gods" because they do not believe that any real deity possesses the properties ascribed by monotheists to their sole deity. Atheists, who do not believe in any deities, do not usually use the term "false god" even though that would encompass all deities from the atheist viewpoint. Usage of this term is generally limited to theists, who believe in some deity or deities, but not in others.