1. a line or border separating two countries: "international crime knows no frontiers"
▪ the extreme limit of settled land beyond which lies wilderness, especially referring to the western US before Pacific settlement: "his novel of the American frontier"
▪ the extreme limit of understanding or achievement in a particular area:"the success of science in extending the frontiers of knowledge"
Word Originlate Middle English: from Old French frontiere, based on Latin frons, front- ‘front’.
