preemption

noun

pre·​emp·​tion prē-ˈem(p)-shən 

1

a

: the right of purchasing before others

especially : one given by the government to the actual settler upon a tract of public land

b

: the purchase of something under this right

2

: a prior seizure or appropriation : a taking possession before others

3

a

: a doctrine in law according to which federal law supersedes state law when federal law is in conflict with a state law

Even without an express provision for preemption, we have found that state law must yield to a congressional Act in at least two circumstances.

—Crosby v. National Foreign Trade Council

called also federal preemption

b

: a doctrine in law according to which the legislation of a superior government (such as a state government) supersedes that of an inferior government (such as a municipal government) in conflicts of law

4

: a policy of launching a preemptive attack in order to prevent a suspected imminent attack

Synonyms

• appropriation
• arrogation
• commandeering
• detainer
• expropriation
• seizure
• takeover
• usurpation

Examples of preemption in a Sentence

longtime residents resented the preemption of their urban neighborhood by this influx of affluent yuppies

Recent Examples on the Web

In March—not long after OpenAI CEO Sam Altman appeared with Donald Trump at the White House to announce a data center initiative—OpenAI sent a set of policy proposals to the White House, which included a federal preemption of state laws. —Andrew R. Chow, Time, 25 June 2025

There is bipartisan agreement about the need for federal preemption of state AI regulations and there is also bipartisan opposition to such a federal moratorium. —Patrick Gleason, Forbes.com, 19 June 2025

At large, federal preemption of stronger state privacy laws hurts everyone, Hayley Tsukayama, associate director of legislative activism at the Electronic Frontier Foundation, wrote in a blog post earlier this month. —Anisha Sircar, Forbes.com, 22 May 2025

No specific preemption law With multiple federal courts having ruled that the state laws are not preempted by existing US laws and regulations, ISPs' best chance at preemption is probably for Congress to implement a nationwide preemption law. —ArsTechnica, 30 May 2025

Word History

Etymology

Medieval Latin praeemption-, praeemptio previous purchase, from praeemere to buy before, from Latin prae- pre- + emere to buy — more at redeem

First Known Use

1602, in the meaning defined at sense 1a

Rhymes for preemption

• exemption
• redemption
• emption

Legal Definition

preemption

noun

pre·​emp·​tion prē-ˈemp-shən 

1

a

: the right of purchasing before others : preemptive right

b

: a right to purchase a tract of public land before others that was given by the government to the actual occupant of the land

Note: This sense of preemption is primarily of historical importance.

2

: a doctrine in conflicts of law: when a superior government (as of a state) has undertaken to regulate a subject its laws supersede those of an inferior government (as of a municipality)

Note: According to the doctrine of preemption, federal law supersedes state law when federal law is in conflict with a state law on a subject or when there is congressional intent to regulate a subject to the exclusion of the states. Federal preemption is based on the supremacy clause of the U.S. Constitution and is closely related to the powers granted Congress in the commerce clause.

3

: an act or instance of preempting

Etymology

Medieval Latin praeemption-, praeemptio previous purchase, from praeemere to buy before