Definition of "euhemerism"

In regard to the Thracian god Zalmosis, the Hellespontic Greeks interpreted his character and attributes according to the scheme of Euemerism.

1846, George Grote, History of Greece, volume I, page 596

Then again there was a period of what is sometimes called Euhemerism - the theory that the gods and goddesses had actually once been men and women, historical characters round whom a halo of romance and remoteness had gathered.

1920, Edward Carpenter, Pagan and Christian Creeds, New York: Harcourt, Brace and Co., published 1921, page 10