n. a wilderness at the edge of a settled area of a country
n. an international boundary or the area (often fortified) immediately inside the boundary
n. an undeveloped field of study; a topic inviting research and development
n. 边界, 边境
[法] 国境, 边境, 边界
1. The explorers traveled to the frontier in search of new lands.
探险者们前往边境寻找新土地。
2. Technology is pushing the frontier of what we can achieve in medicine.
科技正在推动我们在医学领域所能实现的边界。
3. Many great stories take place on the frontier between civilization and wilderness.
许多伟大的故事发生在文明与荒野的边界上。