Definitions for "Rightsholder"
An organization or individual that holds the copyright to a creative work, such as an article, book or image. A rightsholder can be a publisher, author, photographer, etc. or any person, company, estate or trust who receives a right from an original rightsholder (by purchase, gift, inheritance or any other way).
Someone who "holds" or "owns" a right to do something; for instance, a trademark holder or a copyright holder.