IPA: //aɪˈdoʊlən//
KK: /aɪˈdoʊlən/
A ghostly figure or an image that represents something ideal or perfect, often not real or tangible.
In the story, the hero was haunted by the eidolon of his lost love.
Eidolon → It is derived from the Greek word "εἴδωλον" (eidolon), which means an image, phantom, or representation. The term refers to a likeness or an idealized form of something, often used in philosophical contexts to describe an illusion or a shadow of reality.
Imagine an 'image' or 'phantom' that represents something else — that's what eidolon means, a representation or likeness of an idea.
No commonly confused words.