Lewis & Short

Ămestrătus, i, f., a town on the north coast of Sicily, mentioned only by Cic. and Steph. B., now Mistretta, is prob. the same place as the Amastra of Sil. 14, 267; Cic. Verr. 3, 39, 43; Steph. B. s. v.
Hence, Ămestrătīni, ōrum, m., the inhabitants of Amestratus, Cic. Verr. 3, 39, 89.