preemption
    n 1: the judicial principle asserting the supremacy of federal
         over state legislation on the same subject [syn:
         preemption, pre-emption]
    2: the right of a government to seize or appropriate something
       (as property) [syn: preemption, pre-emption]
    3: the right to purchase something in advance of others [syn:
       preemption, pre-emption]
    4: a prior appropriation of something; "the preemption of
       bandwidth by commercial interests" [syn: preemption, pre-
       emption]

Preemption \Pre*["e]mp"tion\ (?; 215), n. [Pref. pre- + emption:
   cf. F. pr['e]emption. See Redeem.]
   The act or right of purchasing before others. Specifically:
   (a) The privilege or prerogative formerly enjoyed by the king
       of buying provisions for his household in preference to
       others. [Eng.]
   (b) The right of an actual settler upon public lands
       (particularly those of the United States) to purchase a
       certain portion at a fixed price in preference to all
       other applicants. --Abbott.
       [1913 Webster]

PRE-EMPTION, intern. law. The right of preemption is the right of a nation 
to detain the merchandise of strangers passing through her territories or 
seas, in order to afford to her subjects the preference of purchase. 1 Chit. 
Com. Law, 103; 1 Bl. Com. 287. 
     2. This right is sometimes regulated by treaty. In that which was made 
between the United States and Great Britain, bearing date the 10th day of 
November, 1794, ratified in 1795, it was agreed, art. 18, after mentioning 
that the usual munitions of war, and also naval materials should be 
confiscated as contraband, that "whereas the difficulty of agreeing on 
precise cases in which alone provisions and other articles not generally 
contraband may be regarded as such, renders it expedient to provide against 
the inconveniences and misunderstandings which might thence arise. It is 
further agreed that whenever any such articles so being contraband according 
to the existing laws of nations, shall for that reason be seized, the same 
shall not be confiscated, but the owners thereof shall be speedily and 
completely indemnified; and the captors, or in their default, the government 
under whose authority they act, shall pay to the masters or owners of such 
vessel the full value of all articles, with a reasonable mercantile profit 
thereon, together with the freight, and also the damages incident to such 
detention." See Mann. Com. B. 3, c. 8. 
     3. By the laws of the United States the right given to settlers of 
public lands, to purchase them in preference to others, is called the 
preemption right. See act of L. April 29, 1830, 4 Sharsw. Cont. of Story, U. 
S. 2212.