Lewis & Short

†† cărăcalla, ae, and cărăcallis, is, f. [Celtic],

  1. I. a long tunic or great-coat, with a hood, worn by the Gauls, and made of different materials, Spart. Sev. 21; Edict. Diocl. p. 21; Hier. Ep. 64, n. 15 (in Mart. 1, 93, 8: Gallica palla).
    From this garment, introduced by him, was named,
  2. II. Masc., the emperor Antoninus Caracalla, Spart. l. l.; id. Car. 9; Aur. Vict. Caes. 21; id. Epit. 21; Aus. Caes. 9, 22.