| 释义 |
the frontier an area where people have never lived before, that not much is known about, especially in the western US before the 20th century〔尤指 20 世纪前美国西部的〕边远地区，荒野地区; 边疆:•a novel about a family's struggle on the American frontier描写一家人在美国边远地区奋斗的小说•space, the final frontier太空，最后的前沿 |