coauthor (n.)

• annalist
• author
• authoress
• bibliographer
• collaborationist
• collaborator
• columnist
• compiler
• composer
• copywriter
• critic
• diarist
• dramatist
• encyclopedist
• essayist
• free-lance
• ghost
• ghostwriter
• humorist
• litterateur
• newspaperman
• novelist
• pamphleteer
• poet
• produce
• reviewer
• scenarist
• scribe
• scriptwriter
• storyteller
• wordsmith
• write
• writer