figment

figment

 

noun

plural noun: figments

1. a thing that someone believes to be real but that exists only in their imagination.

   "it really was Ross and not a figment of her overheated imagination"

   synonyms:

   invention, production, creation, concoction, fabrication;  hallucination, illusion, delusion,mirage, apparition, chimera, fancy, fiction, fable, falsehood, imagining, vision "all this nonsense about ghosts is just a figment of her imagination"