Ghostly describes something that reminds you of a ghost: pale, transparent, eerie, or seeming not quite real. A ghostly figure might appear in the fog, looking faint and colorless. A ghostly sound could be a mysterious whisper or creak that makes you wonder if something supernatural is nearby.

The word captures that spine-tingling feeling when something seems otherworldly or not entirely solid. An abandoned house might have a ghostly atmosphere, especially at twilight when shadows grow long. A ghostly light might flicker in an empty window. Old photographs can have a ghostly quality, showing people from long ago who seem to stare out from another time.

Scientists sometimes use ghostly to describe things that are barely detectable or extremely faint. Astronomers might observe a ghostly nebula at the edge of their telescope's range. The word works because it suggests something that's present but hard to pin down: visible but not quite tangible, like the difference between a solid object and its faint reflection in dark glass.