Petasio, petasiônis, m. g. Varro. A gammon or flitch of bacon.
Petasus, pétasi, pe. cor. m. g. Plaut.An hat. A round couering of an house. After some a boote, or stertup.
Lewis and Short: Latin dictionary
pĕtăsĭo and pĕtăso, ōnis, m., = petasw/n, a leg or pestle of pork, esp. the shoulder (opp. perna, the ham): e Galliā apportantur Romam pernae tomacinae et taniacae, et petasiones, Varr. R. R. 2, 4, 10: pulpam dubio de petasone voras, i. e.
pĕtăsus, i, m., = pe/tasos, a travelling hat or cap, with a broad brim (cf.: pileus, cucullus). I.Lit., Plaut. Ps. 2, 4, 45; 4, 7, 90; id. Am. prol. 143; Arn. 6, 197.—II.Transf., something in the shape of a cap, placed on a building, a cap, cupola, Plin. 36, 13, 19, 92.