Lewis & Short

quā̆drŭ-pĕdans, antis, Part., from the obsol. quadrupedo [quadrupes].

  1. I. Going on four feet, galloping (poet. and postAug.): canterius, Plaut. Capt. 4, 2, 34: equo juxta quadrupedante, galloping close by on horseback, Plin. 8, 45, 70, § 182: sonitus, of a horse galloping, Verg. A. 8, 596.
  2. II. Subst., a galloping horse, a steed, courser (poet.): quadrupedantum Pectora, Verg. A. 11, 614.