Lewis & Short

Pīsae, ārum, f., a very ancient eity of Etruria, a colony of Pisa in Elis, still called Pisa: Alpheae ab origine Pisae, urbs Etrusca solo, Verg. A. 10, 179 Serv.; Just. 20, 1, 11; Luc. 2, 401; Liv. 21, 39.
Hence,

  1. A. Pīsānus, a, um, adj., Pisan: ager, Liv. 39, 2.
    In plur.: Pīsāni, ōrum, m., the Pisans, Liv. 40, 43.
  2. B. ‡ Pīsas, ātis, adj., Pisatic, Pisan, Inscr. Orell. 4048.
  3. C. Pīsātĭlis, e, adj., born at Pisa (for Pisanus), found in Naev., acc. to Fest. p. 210 Müll. (prob. Latinized from the Greek form Πισάτης).