Controller/kənˈtrəʊlər/ Definition 1 of 4Pro Tip 1/3Workplace Roles The word 'controller' often describes senior job positions in companies. She worked hard to become the new quality controller. Pro Tip 2/3Authority Figure 'Controller' implies someone has the power to make decisions in an organization. The traffic controller decided which cars could go first. Pro Tip 3/3High Responsibility A controller is responsible for critical tasks and oversight. The controller oversees the annual financial audit.