AP'ENNINE, adjective [Latin apenninus; ad and penninus, an epithet applied to a peak or ridge of the Alps.] Pertaining to or designating a chain of mountains, which extend from the plains of Piedmont, round the gulf of Genoa, to the center of Italy, and thence south east to the extremity.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI