🔑under·groundadjectiveBrE/ˌʌndəˈɡraʊnd/NAmE/ˌʌndərˈɡraʊnd/[only before noun]🔑underthesurfaceoftheground地下的；地面以下的◆undergroundpassages/caves/streams地下通道/洞穴/溪流◆undergroundcables地下电缆➡ compareovergroundoperatingsecretlyandoftenillegally, especiallyagainstagovernment秘密的，非法的，暗中的，地下的（尤指反政府的）◆anundergroundresistancemovement地下抵抗运动
A city's underground railway/railroad system is usually called the underground (often the Underground) in BrE and the subway in NAmE. Speakers of BrE also use subway for systems in American cities and metro for systems in other European countries. The Metro is the name for the systems in Paris and Washington, D.C. London's system is often called the Tube.城市的地铁系统在英式英语中通常称为 underground（常作 the Underground），在美式英语中为 subway。说英式英语的人指美国城市的地铁亦用 subway，而指其他欧洲国家的地铁则用 metro。the Metro 为巴黎和华盛顿市的地铁名称；伦敦的地铁通常称作 the Tube。
