Ăp'en-nine, a.

a. [Lat. Apenninus; ad and penninus, an epithet applied to a peak or ridge of the Alps. Livy. Celtic pen, or ben, the peak of a mountain, or, in general, a mountain.] Pertaining to, or designating, a chain of mountains extending from the Alps, south of the plains of Piedmont, and around the Gulf of Genoa, to the center of Italy, and thence south-east to the extremity;—used in the pl. as a n.