[] a person who has an official position在职者◆They are looking for a new chief executive, the previous incumbent having left suddenly.由于前任突然离职，他们正在寻找新的行政总裁。a company that has a large share of a particular market主导运营商，市场老大（市场中市场份额大的公司）◆the Swedish telecoms incumbent瑞典电讯市场的主导运营商