under ground

基本解释

They stayed under ground for two days.
他们在地下呆了两天。
《新英汉大辞典》
Innovation is like a bamboo shoot, a bamboo shoots bends many years under ground, and then it just picks its head up like a seedling, and to shoot up very quickly.
创新犹如竹笋，竹笋要在地下生长许多年，然后像幼苗一样把头抬，飞速窜高。
It is very difficult to make basements feel comfortable because they are under ground, usually have insufficient natural light and have the lowest energy in a building.
在地下室里感觉到舒服是很难的，因为它们是在地下，并且缺少足够的自然光，能量也是整个楼中最低的。

Words like these come to mind as visitors enter a world of silence, darkness and cold, almost two hundred thirty meters under the ground.
So how accurate is that picture of Socrates the man who investigates the things aloft and the things under the ground?
所以，苏格拉底在剧中的形象有多准确,就是作为一名调查,一些上天下地之事的人？
耶鲁公开课 - 政治哲学导论课程节选
Again investigating the things aloft under the ground. He is what we would call today a scientist a natural scientist.
能调查上天下地之事的人,即今日我们所谓的科学家,自然科学家。
耶鲁公开课 - 政治哲学导论课程节选

MTRs super train is not ready to glide at top speeds under ground just yet.
FORBES: Bill Nye Should Check Out China; Another "World's Fastest" Train Near Complete

ndgrand ndgrand
Underground is also an adjective.
Theunderground in a city is the railway system in which electric trains travel below the ground in tunnels.
Underground groups and activities are secret because their purpose is to oppose the government and they are illegal.
If you go underground, you hide from the authorities or the police because your political ideas or activities are illegal.

地下
The study on stability of underground structures resisting the uplift load is being adverted.
研究与探讨地下结构的抗浮稳定性问题,日益受到国内外学者的重视。
地下的

地下
It can cause the space in rock underground when the underground coal exploited.
地下煤炭开采必然会形成采空区。
地下的