'Preemptor' definitions:

Definition of 'preemptor'

From: WordNet
noun
Someone who acquires land by preemption [syn: preemptor, pre-emptor]
noun
A bidder in bridge who makes a preemptive bid [syn: preemptor, pre-emptor]

Definition of 'Preemptor'

From: GCIDE
  • Preemptor \Pre*["e]mpt"or\ (?; 215), n. [Cf. L. praeemptor.] One who pre["e]mpts; esp., one who pre["e]mpts public land. [1913 Webster]