1570s, "below the surface," from under + ground (n.). As an adjective, attested from c. 1600; figurative sense of "hidden, secret" is attested from 1630s; adjectival meaning "subculture" is from 1953, from adjectival use in reference to World War II resistance movements against German occupation, on analogy of the dominant culture and the Nazis. Noun sense of "underground railway" is from 1887 (shortened from phrase underground railway, itself attested from 1834).
权威例句
1. Solid low-level waste will be disposed of deep underground.
放射性水平低的固体废料将做地下深埋处理。
2. They are accused of organising and financing an underground youth movement.
他们被指控组织并资助地下青年运动。
3. The inves-tigators found that the underground pipes were badly corroded.
调查人员发现地下管道严重腐蚀。
4. An underground organisation has claimed responsibility for the bomb explosion.
一个地下组织已经声称对这起炸弹爆炸事件负责。
5. Bus routes and railways, both overground and underground, converged on the station.