Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Āpennīnus (better Appennīnus, Verg. A. 12, 703 Cod. Med.; also APENINVS, Inscr. Grut. 204, 18), i, m. [from the Celtic penn, mountain-summit], the mountainchain that passes through the length of Italy, the Apennines, Plin. 3, 5, 7, § 48; conspicuous for height; hence, celsus Appenninus, Hor. Epod. 16, 29: Appenninus nubifer, Ov. M. 2, 226.
Personified: gaudetque nivali Vertice se attollens pater Appenninus ad auras, Verg. A. 12, 703; cf. Mann. Ital. 1, 264 sq.