Frontier

(frŏnt'eer) (Synop., § 130), n. [Fr. frontière, It. frontiera, Sp. frontera, Pg. fronteira, from Lat. frons, forehead, front; Pr. fronteira, forehead. See FRONT.] That part of a country which fronts or faces another country; the marches; the border, confine, or extreme part of a country, bordering on another country; hence, a fortified or guarded position. “Palisadoes, frontiers, parapets.” Shak.

a. 1. Lying on the exterior part; bordering; conterminous; as, a frontier town.

2Sense 2. Acquired on a frontier. “Frontier experience.” W. Irving.

v. i. To constitute or form a frontier. Sir Wm. Temple.