eidôlon

Noun

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.
   • As a species it is extinct; as an eidolon it retains its corporeality – but only if maintained in a state of equipoise.1936, Henry Miller, Black Spring
2. A phantom; a ghost or an elusive entity.
   • Was Philippe d'Orleans seen, this day, 'in the Bois de Boulogne, in grey surtout;' waiting under the wet sere foliage, what the day might bring forth? Alas, yes, the Eidolon of him was,—in Weber's and other such brains.1837, Thomas Carlyle, The French Revolution: A History […], volume (please specify |volume=I to III), London: Chapman and Hall, →OCLC, (please specify the book or page number)
3. An unsubstantial image; a spectre; a phantom.