What is Prize?

Legal Definition
Mar. law, war. The apprehension and detention at sea, of a ship or other vessel, by authority of a belligerent power, either with the design of appropriating it, with the goods and effects it contains, or with that of becoming master of the whole or a part of its cargo. 1 Rob. Adm. R. 228. The vessel or goods thus taken are also called a prize. Goods taken on land from a public enemy, are called booty, (q. v.) and the distinction between a prize and booty consists in this, that the former is taken at sea and the latter on laud.

2. In order to vest the title of the prize in the cap tors, it must be brought with due care into some convenient port for adjudication by a competent court. The condemnation must be pronounced by a prize court of the government of the captor sitting in the country of the captor, or his ally; the prize court of an ally cannot condemn. Strictly speaking, as between the belligerent parties the title passes, and is vested when the capture is complete; and that was formerly held to be complete and perfect when the battle was over, and the spes recuperandi was gone. 1 Kent, Com. 100; Abbott on Shipp. Index, h. t.; 13 Vin. Ab. 51; 8 Com. Dig. 885; 2 Bro. Civ. Law, 444; Harr. Dig. Ship. and Shipping, X; Merl. Repert. h. t.; Bouv. Inst. Index. h. t. Vide Infra praesidia.
-- Bouviers Law Dictionary
Legal Definition
Contracts. A reward which is offered to one of several persons who shall accomplish a certain condition; as, if an editor should offer a silver cup to the individual who shall write the best essay in favor of peace.

2. In this case there is a contract subisting between the editor and each person who may write such essay that he will pay the prize to the writer of the best essay. Wolff, Dr. de la Nat. 675.

3. By prize is also meant a thing which is won by putting into a lottery.
-- Bouviers Law Dictionary
Legal Definition
In admiralty law. A vessel or cargo, belonging to one of two belligerent powers, apprehended or forcibly captured at sea by a war-vessel or privateer of the other belligerent, and claimed as enemy's property, and therefore liable to appropriation and condemnation under the laws of war. See 1 C. Rob. Adm. 228. Captured property regularly condemned by the sentence of a competent prize court. 1 Kent, Comm. 102. In contracts. Anything offered as a reward of contest; a reward offered to the person who, among several persons or among the public at large, shall first (or best) perform a certain undertaking or accomplish certain conditions.
See also
-- Black's Law Dictionary
Legal Definition
Fruits of naval warfare.
-- Ballentine's Law Dictionary