Lewis & Short

spŏlĭārĭum, ii, n. [spolium] (postAug.).

  1. I. Lit., a place in the amphitheatre where the clothes were stripped from the slain gladiators who were dragged thither, Sen. Ep. 93, 10; Lampr. Commod. 18, 3; 19, 3.
  2. II. Transf., a den of robbers or murderers, a cutthroat place, Sen. Prov. 3, 7; id. Contr. 5, 33; Plin. Pan. 36, 1.