B2 to tell someone confidently that something is true, especially so that they do not worry

中文解释

（尤指为消除其忧虑而）确定地对…说，向…保证，使确信;让…放心 assure sb of sth The unions assured the new owners of the workers\' loyalty to the company. 工会向新企业主保证，工人们对公司是忠诚的。