In Buddhism, the term "시주" (施主) refers to the act of giving material goods such as money or food to monks or temples, or a person who engages in such acts. It can also be translated as "donor" or "patron." The term "단월" or "단나" is also used to refer to 시주. The concept of 시주 is an important practice in Buddhism, and there are many historical records of 시주 in Korea. It is considered a virtuous act that supports the spiritual practice of monks and contributes to the well-being of the Buddhist community.
Source: https://encykorea.aks.ac.kr/Article/E0079294