preemption

Definition of preemption

Etymology

From Medieval Latin prae�"mptiō (“previous purchase”), from praeemō (“buy before”), from Latin prae- (“before”) + emō (“buy”).

Noun

preemption (plural preemptions)

1. The purchase of something before it is offered for sale to others.
2. The purchase of public land by the occupant.
3. (law) The displacement of a lower jurisdiction's laws when they conflict with those of a higher jurisdiction.