Synonyms for Vitiate (same or very similar meaning)
WordNet sense 1 (corrupt morally or by intemperance or sensuality):
corrupt, debase, debauch, demoralize, deprave, misdirect, pervert, profane, subvert, demoralise, pervertWordNet sense 2 (make imperfect):
deflower, impair, mar, spoilWordNet sense 3 (take away the legal force of or render ineffective):
invalidate, voidFrom the ODE community, based on WordNetadd/edit