preemption
pre.emp.tion \-'em(p)-sh*n\ n [ML praeemptus, pp. of praeemere to buy before, fr. L prae- p]re- + emere to buy - more at REDEEM 1a: the right of purchasing before others; esp : one given by the g overnment to the actual settler upon a tract of public land 1b: the purchase of something under this right 2: a prior seizure or appropriation : a taking possession before others