Level 4 · word 5,745 of 20,000
frontiers
/frənˈtɪrz/
American

- 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。