Noun

• S: (n) ghost, shade, spook, wraith, specter, spectre (a mental representation of some haunting experience) "he looked like he had seen a ghost"; "it aroused specters from his past"
• S: (n) ghostwriter, ghost (a writer who gives the credit of authorship to someone else)
• S: (n) ghost (the visible disembodied soul of a dead person)
• S: (n) touch, trace, ghost (a suggestion of some quality) "there was a touch of sarcasm in his tone"; "he detected a ghost of a smile on her face"

Verb

• S: (v) ghost (move like a ghost) "The masked men ghosted across the moonlit yard"
• S: (v) haunt, obsess, ghost (haunt like a ghost; pursue) "Fear of illness haunts her"
• S: (v) ghost, ghostwrite (write for someone else) "How many books have you ghostwritten so far?"