1. frontier - Noun
2. frontier - Adjective
3. frontier - Verb
4. Frontier - Proper noun
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.
An outwork.
Lying on the exterior part; bordering; conterminous; as, a frontier town.
Of or relating to a frontier.
To constitute or form a frontier; to have a frontier; -- with on.
Source: Webster's dictionaryWhere the frontier of science once was is now the centre. Georg Christoph Lichtenberg
Russia, France, Germany and China. They revere their writers. America is still a frontier country that almost shudders at the idea of creative expression. James A. Michener
Life is wide, limitless. There is no border, no frontier. Bruce Lee
My work explores the frontier between rationalism and superstition and the wavering boundary between the two. David Almond
People always underestimate the impact of technology. To give you an example: In the 1970s the frontier for offshore development was 200 meters, today it is 4,000 meters. Daniel Yergin
A fair wife and a frontier castle breed quarrels. English Proverb