covenant
noun [ C ] uk/ˈkʌv.ən.ənt/ us/ˈkʌv.ən.ənt/
盟约;契约;协定;承诺
a formal agreement or promise between two or more people
The contract contained a restrictive covenant against building on the land. 该合同包含严格的限制条款，禁止在这块土地上建筑施工。
finance & economics UK specialized（尤指定期向慈善机构捐款的）合同，约定
a formal agreement to pay a fixed amount of money regularly, especially to a charity