Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Phintĭa, ae, f., a city in Sicily, now Alicata or Licata, Cic. Verr. 2, 3, 83, § 192.
Hence, Phintĭenses, ĭum, m., the inhabitants of Phintia, the Phintians, Plin. 3, 8, 14, § 91.