Lewis & Short

commissĭo, ōnis, f. [committo].

  1. I. (Acc. to committo, I. B.) Lit., a setting or bringing together in contest; hence, the beginning of a contest (in the public games, etc.): tecum ago, ut jam ab ipsā commissione ad me … persequare, etc., Cic. Att. 15, 26, 1; 16, 5, 1: ludorum, Suet. Aug. 43; id. Galb. 6; Plin. Ep. 7, 24, 6; id. Pan. 54, 1; Macr. S. 2, 7.
    1. B. Meton., a speech at the opening of the games; hence, a prize declamation, ostentatious speech, ἀγώνισμα, Calig. ap. Suet. Calig. 53; Suet. Aug. 89; v. Casaub. in h. ll.
  2. II. (Acc. to committo, II. B. 4.) A perpetration, commission: piaculi, Arn. 4, p. 148.