A "guest author" is someone who is not a permanent writer for a publication or website, but is invited or allowed to write an article or story for them. Full definition
From here you can access our dating articles, both those articles written by me, your online guide, and those written by guest authors. (singledating.com)
It's been thoroughly reviewed and updated to meet current best practices, and it includes a large amount of new information and content — including guest authors on key topics throughout the book. (lifelearn.com)
We occasionally accept articles from guest authors from other top career blogs. (resume-resource.com)