I like "diminish".

I don't want to copy/paste these definitions below, but Stack Exchange won't let me give an answer of less than 30 characters.

[diminish]

1. to make or cause to seem smaller, less, less important, etc.; lessen; reduce.

4. to detract from the authority, honor, stature, or reputation of; disparage. 

http://dictionary.reference.com/browse/diminish