Lewis & Short

essĕdārĭus, a, um, adj. [essedum], of or belonging to a war-chariot: mulier, Petr. 45, 7.
Hence, as subst.: essedari-us, i, m.

  1. I. A fighter in a (Gallic or British) war-chariot, Caes. B. G. 4, 24, 1; 5, 15, 1; 5, 19, 1; Cic. Fam. 7, 6 fin.
  2. II. In the Roman circus, a gladiator, Petr. 36, 6; Suet. Calig. 35; id. Claud. 21; Inscr. Orell. 2566; v. essedum.