Lewis & Short

Cŏsa, ae (on coins also Cossa; access. form Cŏsae, ārum, Verg. A. 10, 168), f., = Κόσσα and Κόσσαι.

  1. I. An ancient town in Etruria, not far from the coast, now Ansedonia, above Orbitello, Mel. 2, 4, 9; Liv. Ep. 14; id. 22, 11, 6; Plin. 3, 5, 8, § 51; Vell. 1, 14, 6; Tac. A. 2, 39 al.
    Hence,
    1. B. Cŏ-sānus (Coss-), a, um, adj., of Cosa: litus, Plin. 3, 6, 12, § 81: portus, Liv. 22, 11, 6: praedia, Suet. Vesp. 2.
      Subst.,
      1. 1. Cŏsā-num, i, n.
          1. (α) The territory around Cosa, Caes. B. C. 1, 34.
          2. (β) A country seat near Cosa, Cic. Att. 9, 6, 2; 15, 27, 1.
      2. 2. Cŏsā-ni, ōrum, m., the inhabitants of Cosa, Liv. 33, 24, 8.
  2. II. A town in Lucania, in the territory of the Thurini, the same as Consa or Compsa, Caes. B. C. 3, 22 dub.