externality

n. 外形, 外在性

名词复数:externalities 

ex.ter.nal.i.ty

n.（名词）
【复数】 ex.ter.nal.i.ties
The condition or quality of being external or externalized.
客观性：客观的或使客观化的条件或性质


Something that is external.
外部事物
An incidental condition that may affect a course of action:
外部因素：可能影响行动的进程的偶然条件：
例句：
.Our economic system treats environmental degradation as an externality—a cost that does not enter into the conventional arithmetic that determines how we use our resources.(Barry Commoner)
.我们的经济系统作为外部偶然因素引起环境的退化——这个没有列入常规计算的价值决定我们如何利用我们的资源.(巴里·康芒纳)