Source : Webster's Revised Unabridged Dictionary (1913)

Euhemerism \Eu*hem"er*ism\n. [L. Euhemerus, Gr. ? a philosopher,
   about 300 ?.]
   The theory, held by Euhemerus, that the gods of mythology
   were but deified mortals, and their deeds only the
   amplification in imagination of human acts.