debase - verb

• corrupt morally or by intemperance or sensuality
• lower in value by increasing the base-metal content
• corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones

debase - thesaurus

adulterate   alloy   corrupt   debauch   demoralise   demoralize   deprave   dilute   load   misdirect   pervert   profane   stretch   subvert   vitiate