degrade
Definitions
To lower the character, quality, or value of something or someone.
To cause a complex substance to break down into simpler substances.
To reduce someone to a lower rank, status, or position.
Examples
Constant exposure to sunlight will eventually degrade the quality of the plastic.
The politician's offensive remarks served only to degrade his reputation in the eyes of the public.
Pollution continues to degrade the natural environment of the local wetlands.