English Dictionary

ground zero

/ˌɡɹaʊnd ˈzɪəɹəʊ/

noun

Originally, the point on the land or water surface below which a nuclear bomb detonates in the air; now also the point on such a surface at or above the detonation.

The memorial at ground zero is a solemn reminder of the tragic events that took place on September 11th.

意味（1）

Originally, the point on the land or water surface below which a nuclear bomb detonates in the air; now also the point on such a surface at or above the detonation.

Some of the construction details (reinforcing rod splices, for example) [in Hiroshima and Nagasaki, Japan] were often poor, and much of the concrete was definitely weak; thus some reinforced concrete buildings collapsed and suffered structural damage when within 2,000 feet of ground zero, and some internal wall paneling was demolished even up to 3,800 feet.

意味（2）

(by extension) The location of any disaster or violent assault.

This is ground zero, she said. If regulators don't adopt a zero tolerance for violations of standards then what we will have are places that are going to have unacceptable environmental damage.

意味（3）

(figuratively) The point at which something begins.

James Meredith's forced admission was a milestone in upending the old order in America's most segregated state, a kind of race relations ground zero.