n. | 1. | That part of a country which fronts or faces another country or an unsettled region; the marches; the border, confine, or extreme part of a country, bordering on another country; the border of the settled and cultivated part of a country; |
2. | (Fort.) An outwork. | |
a. | 1. | Lying on the exterior part; bordering; conterminous; |
2. | Of or relating to a frontier. | |
v. i. | 1. | To constitute or form a frontier; to have a frontier; - with on. |
Noun | 1. | frontier - a wilderness at the edge of a settled area of a country; "the individualism of the frontier in Andrew Jackson's day" |
2. | frontier - an international boundary or the area (often fortified) immediately inside the boundary | |
3. | frontier - an undeveloped field of study; a topic inviting research and development; "he worked at the frontier of brain science" |