Lewis & Short

† pĕtăsus, i, m., = πέτασος, a travelling hat or cap, with a broad brim (cf.: pileus, cucullus).

  1. I. Lit., Plaut. Ps. 2, 4, 45; 4, 7, 90; id. Am. prol. 143; Arn. 6, 197.
  2. II. Transf., something in the shape of a cap, placed on a building, a cap, cupola, Plin. 36, 13, 19, § 92.