n.边疆，边境；边界，边缘；尚待开发的领域；adj.边疆的，边界的；新垦地的，边地的；开拓的； 变形： 复数：frontiers 双语释义：n.(名词)[C]边界,边境 the edge of the land of one country[S]开发地区的边缘,边远地区 the border between settled and wild country[P]尚待开发的领域 a border between what is known and what is unknown英英释义： frontier[