petasus
From LSJ
Latin > English (Lewis & Short)
pĕtăsus: i, m., = πέτασος>,
I 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.