ghost (Noun) — A mental representation of some haunting experience. ex. "he looked like he had seen a ghost"
ghost (Noun) — A writer who gives the credit of authorship to someone else.
ghost (Noun) — The visible disembodied soul of a dead person.
ghost (Noun) — A suggestion of some quality. ex. "he detected a ghost of a smile on her face"
ghost (Noun) — A faint false image formed in an optical or display device, e.g. by reflection from the surfaces of one or more lenses.
ghost (Verb) — Move like a ghost. ex. "The masked men ghosted across the moonlit yard"
ghost (Verb) — Haunt like a ghost; pursue.
ghost (Verb) — Write for someone else.