Preemption or pre-emption may refer to:
Legal
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FDA preemption, legal theory in the United States that exempts product manufacturers from tort claims regarding Food and Drug Administration approved products
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Federal preemption
In the law of the United States, federal preemption is the invalidation of a U.S. state law that conflicts with federal law. The rules of preemption seek to restrict it to only where it is explicit or necessary. In the course of adjudicating ...
, displacement of U.S. state law by U.S. Federal law
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Pre-emption right
A pre-emption right, right of pre-emption, or first option to buy is a contractual right to acquire certain property newly coming into existence before it can be offered to any other person or entity. It comes from the Latin verb ''emo, emere, emi, ...
s, the right of existing shareholders in a company to buy shares offered for sale before they are offered to the public
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Preemption (land) Preemption was a term used in the nineteenth century to refer to a settler's right to purchase public land at a federally set minimum price; it was a right of first refusal. Usually this was conferred to male heads of households who developed the ...
, a type of land transfer in the United States, as in the Preemption Act of 1841
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Preemption Line
The Preemption Line (also spelled Pre-Emption) divided the aboriginal lands of western New York State awarded to New York from those awarded to the Commonwealth of Massachusetts by the Treaty of Hartford of 1786. It was defined as the meridian (n ...
, the line dividing Indian lands awarded to New York, from those awarded to the Commonwealth of Massachusetts in 1786
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State preemption
In United States law, state preemption is the invalidation of some action by, or the wresting of power from, a portion of the state government (more often than not a municipality or other part of the state government that only exercises power withi ...
, displacement of U.S. municipal law by state law
Other
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Preempt
Preempt (also spelled "pre-empt") is a bid in contract bridge whose primary objectives are (1) to thwart opponents' ability to bid to their best contract, with some safety, and (2) to fully describe one's hand to one's partner in a single bid. A ...
, a type of bid and a bidding tactic in contract bridge
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Preemption (computing)
In computing, preemption is the act performed by an external scheduler — without assistance or cooperation from the task — of temporarily interrupting an executing task, with the intention of resuming it at a later time. This preemptive s ...
, the interruption of a computer process without its cooperation in order to perform another task
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Preemptive war
A preemptive war is a war that is commenced in an attempt to repel or defeat a perceived imminent offensive or invasion, or to gain a strategic advantage in an impending (allegedly unavoidable) war ''shortly before'' that attack materializes. I ...
or preemptive strike
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Traffic signal preemption
Traffic signal preemption (also called traffic signal prioritisation) is a system that allows an operator to override the normal operation of traffic lights. The most common use of these systems manipulates traffic signals in the path of an emerg ...
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