Lewis & Short

Carsĕŏli, ōrum, m., = Καρσέολοι, a town of the Æqui, in Latium, now the village Carsoli, Liv. 10, 3, 2; 10, 13, 1; 10, 27, 9; 10, 29, 15; Vell. 1, 14, 5; Ov. F. 4, 683.
Hence,

  1. B. Carsĕŏlānus, a, um, adj., of Carseoli: ager, Col. 3, 9, 2: lex, Ov. F. 4, 710.
    Subst.: Carsĕŏlāni, ōrum, m., the inhabitants of Carseoli, Plin. 3, 12, 17, § 106.
    And in neutr.: in Carseolano, in the region of Carseoli, Plin. 17, 23, 35, § 213.