Level 4 · word 5,745 of 20,000

frontiers

/frənˈtɪrz/ American
Picture: frontiers
  • n. 边界, 未知领域
Definition
  • n. the borders between countries, or the limits of an area not yet explored
Example
Scientists keep exploring new frontiers in medicine and technology.
科学家们不断在医学和科技领域探索新的前沿。