Lewis & Short

con-testor, ātus, 1, v. dep., to take or call to witness.

  1. I. Prop.
    1. A. In gen.: deos hominesque, Cic. Verr. 2, 4, 29, § 67; cf. deos, Caes. B. G. 4, 25: caelum noctemque, Cic. Fl. 40, 102.
      Far more freq.,
          1. (β) In pass. signif.: contestari, to be called to witness, P. Aufidius ap. Prisc. p. 793 P.
    2. B. Esp., jurid. t. t.: litem, to introduce a lawsuit by calling witnesses, to bring an action, to set on foot, Cic. Att. 16, 15, 2; id. Rosc. Com. 18, 53; Gell. 5, 10, 8; Cod. Just. 3, 9 al.; cf. Paul. ex Fest. p. 57, 18 Müll.
          1. (β) In pass. signif.: lis contestatur, Lex Gall. Cisalp. 1, 48; Dig. 9, 4, 26, § 5 al.; so, lite contestata, Cic. Rosc. Com. 11, 32; 12, 35: cum lis contestata cum Flavio damni injuriā esset, id. ib. 18, 54; Dig. 24, 3, 22 et saep.; cf. Prisc. p. 793 P.
          2. (γ) contestātō, adverbially, by aid of witnesses, Dig. 15, 4, 1; 25, 3, 1 al.
  2. II. Trop., part. perf.: contestatus, in pass. signif., proved by witness, tried: ab hac perenni contestataque virtute majorum, proved, Cic. Fl. 11, 25.