The crossword solution for the term 'Biller's Partner' is COOER, which stands for Chief Operating Officer. The Chief Operating Officer is a senior executive responsible for managing the day-to-day operations of a company. They are typically responsible for overseeing the production and delivery of goods and services, as well as managing the staff and resources necessary to do so. The COO works closely with the CEO and other executives to ensure that the company is running efficiently and meeting its goals.