Other forms: ghostwritten; ghostwriting; ghostwrote; ghostwrites
To ghostwrite something is to pen a book, speech, play, or any other work that will be published under someone else's name. A pop star might pay someone to ghostwrite his memoirs.
When a screenwriter can't figure out the perfect ending for the movie she's working on, she might hire someone to ghostwrite the screenplay. The original screenwriter will get her name in the credits, while the ghostwriter will get a paycheck. Sometimes people who aren't skilled writers will employ an expert to ghostwrite something for them — like a celebrity who wants to see their name on the cover of a book but doesn't have time to do the actual writing.