corrosion
noun [ U ] uk/kəˈrəʊ.ʒən/ us/kəˈroʊ.ʒən/
腐蚀，侵蚀;腐蚀（或侵蚀）作用的生成物
the process of corroding, or metal that has been corroded
There was a lot of corrosion on the bottom of the car. 汽车底部锈迹斑斑。
figurative We are witnessing the corrosion of moral standards within our society. 我们见证了社会道德的沦丧。