ghost
noun.
a mental representation of some haunting experience
he looked like he had seen a ghost|it aroused specters from his past
noun.
a writer who gives the credit of authorship to someone else
Synonym: ghostwriter
noun.
the visible disembodied soul of a dead person
noun.
a suggestion of some quality
there was a touch of sarcasm in his tone|he detected a ghost of a smile on her face
Synonym: trace, touch
verb.
move like a ghost
The masked men ghosted across the moonlit yard
verb.
haunt like a ghost; pursue
Fear of illness haunts her
Synonym: haunt, obsess
verb.
write for someone else
How many books have you ghostwritten so far?
Synonym: ghostwrite