define eidolon
eidolon (plural eidola or eidolons) 1  An image or representation of an idea; a representation of an ideal form; an apparition of some actual or imaginary entity, or of some aspect of reality. 1936, Henry Miller, Black Spring: As a species it is extinct; as an eidolon it retains its corporeality â but only if maintained in a state of equipoise.