pre-emption/ˌpri:ˈempʃn; prɪ`ɛmpʃən/ n[U]1 (fml 文)(a) purchase by one person, group, etc before others have the chance to buy 优先购买.(b) right to do this 优先购买权.2 obtaining or preventing (sth) by acting in advance 抢先行动以占有或阻止（某事物）.
牛津英汉双解词典