The term 'proprietor' is used to describe someone who holds a certain position or has a certain role. This could include a POSSESSOR, HOLDER, OWNER, SOLE, or OPERATOR. A POSSESSOR is someone who has possession of something, while a HOLDER is someone who has something in their possession. An OWNER is someone who has the right to possess something, and a SOLE is someone who is the only one with that right. Finally, an OPERATOR is someone who is responsible for running or managing something. All of these terms can be used to describe a proprietor.