noun
1.
Synonyms: delusion 1, hallucination, ignis fatuus, illusion, mirage
Related Word: fabrication, fiction, invention
2.
Synonyms: apparition , eidolon, ghost, phantom, revenant, shade, shadow, specter, spectrum, spirit
3.
Synonyms: fancy 4, daydream, dream, fantasy ( or phantasy), nightmare, vision