Lewis & Short

2. Ardĕa, ae, f. [v. arduus], = Ἀρδέα, the capital of the Rutuli, six leagues south of Rome; acc. to the myth, it was burned by Æneas, and from its ashes the heron (ardea) was produced, Ov. M. 14, 573; Verg A. 7, 411; cf. Serv. ad h. l.; Mann. Ital. I. 617; Müll. Roms Camp. 2, 296-312.
Hence, Derivv.,

  1. A. Ardĕas, ātis, adj. (old nom. Ardeātis, like Arpinātis, Cato ap. Prisc. p. 629 P.), of or belonging to Ardea, Ardean: in agro Ardeati, Cic. N. D. 3, 18, 47: Ardeas templum, Plin. 35, 10, 37, § 115.
    Hence, in the plur.: Ardeātes, ium, m., the inhabitants of Ardea, Liv. 5, 44; 4, 7.
  2. B. Ardĕātīnus, a, um, adj. (rare for Ardeas), Ardean: praedium, Nep. Att. 14, 3 (Halm, Arretinum); absol., in Ardeatino (sc. agro), Sen. Ep. 105.