phantasm

/ˌfænˈtæzəm/

Other forms: phantasms

If you've ever caught a glimpse of a ghostly figure late at night, you've seen a phantasm — something that only appears to exist.

A phantasm is an apparition or ghost, something that seems very real when you see it but less so as time goes by. It's not real, but an illusion or brief hallucination that might be caused by a vivid dream, illness, or a lack of sleep. The Greek root is phantasma, "image or phantom," with in turn comes from phantazein, "to make visible."

Definitions of phantasm

1. noun

   something existing in perception only
   synonyms: apparition, fantasm, phantasma, phantom, shadow

   types:

   UFO, flying saucer, unidentified flying object

   an (apparently) flying object whose nature is unknown; especially those considered to have extraterrestrial origins

   Flying Dutchman

   a phantom ship that is said to appear in storms near the Cape of Good Hope

   ghost, shade, specter, spectre, spook, wraith

   a mental representation of some haunting experience

   type of:

   illusion, semblance

   an erroneous mental representation
2. noun

   a ghostly appearing figure
   synonyms: apparition, fantasm, phantasma, phantom, specter, spectre

   types:

   Flying Dutchman

   the captain of a phantom ship (the Flying Dutchman) who was condemned to sail against the wind until Judgment Day

   type of:

   disembodied spirit, spirit

   any incorporeal supernatural being that can become visible (or audible) to human beings