preemption n. (1)〈美〉优先购买权；先买权；(通过抢先占用等取得的)公共土地优先购买权 (2)(国际法)强制收购权 一国在其领土内扣留运经该国领土的他国国民财产以便本国国民购买的权利，现该权利仅限于战时且必须是在如允许该财产运至终点将会损害收购国利益的情况下才能行使。 (3)(英格兰古法)王室征购官(为王室供应需要可以估定价格〔appraised price〕购买物品)的优先购买权 (4)〈美〉(在某些全国性问题上)联邦法优先(于州法的)原则；(在某一特定领域)州法优先(于地方法的)原则
preemption (pree-emp-sh[schwa]n), n. 1. The right to buy before others. See RIGHT OF PREEMPTION. [Cases: Contracts 16; Sales 24; Vendor and Purchaser 18(.5). C.J.S. Contracts §§ 37–41, 44, 46, 55–56, 58; Sales §§ 41–42; Vendor and Purchaser§§ 98–100, 103–106, 115–116.] 2. The purchase of something under this right. 3. An earlier seizure or appropriation. 4.