criticality

名词 criticality:

1. a state of critical urgency
   同义词：criticalness, cruciality
2. a critical state; especially the point at which a nuclear reaction is self-sustaining

crit.i.cal.i.ty

n.（名词）
The quality, state, or degree of being of the highest importance:
临界状态：接近顶尖重要的性质、状态或程度：
例句：
.The challenge of our future food supply is approaching criticality.(New York Times)
.我们未来食物供应的挑战已接近临界状态.(纽约时报)

Physics The point at which a nuclear reaction is self-sustaining.
【物理学】 临界点：核反应能够自我维持的一个点