Frontier

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; as, the frontier of civilization.
	2.	(Fort.) An outwork. Palisadoes, frontiers, parapets. - Shak.
a.	1.	Lying on the exterior part; bordering; conterminous; as, a frontier town.
	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"

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