What is Litis Contestatio?

Legal Definition
Civil law. "Contestari." It is when each party to a suit (uterque reus) says "Teste estote." It was therefore, so called, because persons were called on by the parties to the suit "to bear witness," "to be witnesses." It is supposed that this contestatio was the usual termination of certain acts before the magistratus or in jure, of which the persons called to be witnesses were at some future time to bear record before the judex, in judicio. The Iis contestata, in the system of Justinian, consisted in the statements made by. the parties to a suit before the magistrate respecting the claim or demand, and the answer or defence to it. When this was done, the cause was ready for hearing. Savig. Traite de Droit Romain, tom. vi. ยง cclviii.; Smith, Dict. Gr. & Rom. Antiq. h. v. The contesting of the suit, or pleading the general issue. Vide 2 Bro. Civ. and Adm. Law, 358.
-- Bouviers Law Dictionary
Legal Definition
Lat In the civil and canon law. Contestation of suit; the process of contesting a suit by the opposing statements of the respective parties; the process of coming to an issue; the attainment of an issue; the issue itself. In the practice of the ecclesiastical courts. The general answer made by the defendant, in which he denies the matter charged against him in the libel. Halllfax, Civil Law, b. 3, c. 11, no. 9. In admiralty practice. The general Issue. 2 Browne, Civil & Adm. Law, 358, and note.
-- Black's Law Dictionary
Legal Definition
(Civil and Canon Law) The contest of a suit; a general denial in an ecclesiastical suit.
-- Ballentine's Law Dictionary