Debase

verb
corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones
“adulterate liquor”
Similar: load, adulterate, stretch, dilute
verb
lower in value by increasing the base-metal content
Similar: alloy
verb
corrupt morally or by intemperance or sensuality
“debauch the young people with wine and women”
Similar: corrupt, pervert, subvert, demoralize, demoralise, debauch