1. (

• preemption ,
• pre-emption

) the judicial principle asserting the supremacy of federal over state legislation on the same subject ;

2. (

• preemption ,
• pre-emption ,

) the right of a government to seize or appropriate something (as property) ;

3. (

• preemption ,
• pre-emption

) the right to purchase something in advance of others ;

4. (

• preemption ,
• pre-emption

) a prior appropriation of something; "the preemption of bandwidth by commercial interests" ;