frontier: Meaning and Definition of

fron•tier

1. the part of a country that borders another country; boundary; border.
2. the land or territory that forms the furthest extent of a country's settled or inhabited regions.
3. Often, the frontiers of physics.
1. the limit of knowledge or the most advanced achievement in a particular field:the frontiers of physics.
2. an outer limit in a field of endeavor, esp. one in which the opportunities for research and development have not been exploited:the frontiers of space exploration.
4. boundary (def. 2).

1. of, pertaining to, or located on the frontier: a frontier town.