Lewis & Short

Synnăda, ōrum, n., a town in Phrygia Major, famous for its marble, now Afioum Karahissar, Cic. Fam. 3, 8, 3 sq.; 15, 4, 2; id. Att. 5, 20, 1.
Also called Synnăda, ae, f., Claud. in Eutr. 2, 273; and Syn-nas, ădis, Mart. 9, 76, 8; Stat. S. 1, 5, 37; 2, 2, 87; Plin. 5, 29, 29, § 105.
Hence,

  1. A. Synnădensis, e, adj., of or belonging to Synnada: forum, Cic. Att. 5, 21, 9.
  2. B. Synnădĭcus, a, um, adj., Synnadic: lapis, Plin. 35, 1, 1, § 3.
  3. C. Synnas, ădis, adj. f., Synnadic: columnae, of Synnadic marble, Capitol. Gord. III. 32.