patron
A person who regularly supports or uses a place or service.
A patron is someone who regularly supports a person, cause, or establishment with their money, encouragement, or influence. When you become a patron of your local library, you use it often and maybe donate books or funds to help it thrive. Famous artists throughout history relied on wealthy patrons who paid them to create paintings, sculptures, or music, allowing them to focus on their art instead of worrying about earning a living.
The word also describes a regular customer of a business. If you visit the same bookstore every week, you're a patron of that bookstore. Restaurant owners value their loyal patrons who keep coming back. Libraries call their visitors patrons rather than customers because libraries serve the public good, not just profit.
A patron saint is a saint believed to protect a particular group, place, or activity. Saint Christopher is the patron saint of travelers, while Saint Cecilia is the patron saint of musicians.
When someone becomes your patron, they believe in what you're doing enough to help make it possible.