DEBASE

[verb] [T] - to reduce in quality or valueThe word 'sale' has been debased by shops who hold sales at all times of the year.Our world view has become debased. We no longer have a sense of the sacred. The kebab and hamburger have become debased fast-food versions of their original selves.To debase the coinage/currency is to lower the value of a coin by making it from a less valuable metal.