FRONTIER

[noun] [C] - a border between two countries, or (esp. in the past in the United States) a border between cultivated land where people live and wild landSome of the frontier between Germany and Poland follows the course of the river OderNepal has frontiers with both India and China.Heavy fighting took place last night at the frontier.There have been reports of an incident which occurred on the frontier.They lived in a town close to the frontier.A frontier is also a border between what is known and not known.Many researchers enjoy the exhilaration of working at the frontiers of knowledge.