Lewis & Short

Syrācūsae, ārum (scanned Syrăcūsae, Aus. Clar. Urb. 10, 1), f., = Συράκουσαι, the city of Syracuse in Sicily, now Siragossa, Cic. Verr. 2, 4, 52, § 115 sqq.; Liv. 24, 3 sq.; Ov. F. 4, 873; Sil. 14, 277; Nep. Timol. 3; Vell. 2, 15; Plin. 3, 8, 14, § 89.
Hence,

  1. A. Syrācūsānus, a, um, adj., of or belonging to Syracuse, Syracusan: lautumiae, Cic. Verr. 2, 5, 27, § 68: conventus, id. ib. 2, 3, 13, § 32: mensae, id. Fin. 2, 28, 92: esne tu Syracusanus? from Syracuse, Plaut. Men. 5, 9, 50.
    Subst.: Syrācūsāni, ōrum, m., the inhabitants of Syracuse, the Syracusans, Cic. Verr. 2, 5, 28, § 71 sq. al.
  2. B. Syrācūsĭus, a, um, adj., acc. to the Gr. Συρακούσιος, Syracusan (very rare): mensae, Cic. Tusc. 5, 35, 100: Philistus, id. de Or. 2, 13, 57.
    Subst.: Syrācūsĭi, ōrum, the Syracusans, Plin. 7, 56, 57, § 208.
    Collat. form Syrācŏsĭus, a, um, acc. to the Gr. Συρακόσιος, Syracusan: Dio, Cic. Off. 1, 44, 155: versus, Verg. E. 6, 1: ars, Ov. F. 6, 277: urbs, id. P. 4, 3, 39: poëta, id. Ib. 551: senex, i. e. Archimedes, Claud. Epigr. 18.
    Subst.: Syrācŏsĭi, ōrum, m., the Syracusans, Cic. Div. 1, 20, 39.