adj.地下的；秘密的
adv.在地下；秘密地
n.地下；地铁；地道；秘密活动
Listen to the Sound From Underground. 听听地下的声音。
Underground water that is held in the soil and in pervious rocks. 土壤和能渗透的岩石中含有的地下的水。
He is well known for his reports on underground crime and gangs. 他因为关于报道秘密的犯罪和帮派而出名。
The insurrectionary detachments started in Yunghsin as an underground force,but they have come into the open since we captured the entire county. 暴动队始于永新，原是秘密的，夺取全县以后，公开了。
用作副词 (adv.)Moles stay underground most of the time. 钱鼠大部分时间住在地下。
Torrential rivers are rumbling deep underground. 急流在地下深处隆隆奔腾。
They were making a plan underground. 他们在秘密地策划。
用作名词 (n.)Moles stay underground most of the time. 钱鼠大部分时间住在地下。
Torrential rivers are rumbling deep underground. 急流在地下深处隆隆奔腾。
I obtained it for one pound in the underground. 这是我在地铁花一英镑买来的。
They dived into the Underground to escape the rain. 他们急忙钻进地铁避雨。
The prisoner escaped by digging an underground wunnel. 囚犯挖了一条地道逃跑了。
We were forced to move underground, to the tunnels here. 我们被迫撤向地下，来到了这些地道里。
The spy never told his family about his underground activities. 这位间谍从未把他的秘密活动告诉家里人。
