proprietor
n.the owner of a business, such as a shop, hotel, or restaurant. You use this word when you want to sound more formal than just saying 'owner'.
n.the legal owner of a business establishment or property. Often used in legal or commercial contexts to specify the person with the right of possession.
“The proprietor of the small bookstore greeted us at the door.”
“After the original proprietor retired, his daughter took over the management of the family hotel.”
“The local newspaper interviewed the proprietor of the historic inn to discuss the challenges of maintaining a heritage building in the modern economy.”
More formal than 'owner'; frequently used in legal documents and business signage.
“The change would be even harder for landscapers who work as sole proprietors, with a single vehicle and limited space for charging and storing equipment.”
Probably from proprietary + -or.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.