ground zero noun
Learner's definition of GROUND ZERO
[noncount]
1
: the point on the earth's surface directly above, below, or at which an explosion (especially a nuclear explosion) occurs(尤指核弹的)爆心投影点,地面零点
2
: the central point in an area of fast change or intense activity(某区域发生快速变化或剧烈活动的)中心点 3
: the beginning state or starting point起始点;开始状态