Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. Arna, ae, f., a town in Umbria, a mile east of Perusia, now Civitella d’Arno, Sil. 8, 458; Inscr. Orell. 91; cf. Mann. Ital. I. 483.
Hence, Arnātes, um, m., the inhabitants of Arna, Plin. 3, 14, 19, § 113; Inscr. Orell. 90 and 5005.
‡ 2. arna, ae, f., a lamb, Paul. ex Fest. p. 17 Müll. (v. aries init.).