verb (used with object), vi·ti·at·ed, vi·ti·at·ing.
- to impair the quality of; make faulty; spoil.
- to impair or weaken the effectiveness of.
- to debase; corrupt; pervert.
- to make legally defective or invalid; invalidate: to vitiate a claim.
- to make faulty or imperfect
- to debase, pervert, or corrupt
- to destroy the force or legal effect of (a deed, etc)to vitiate a contract
1530s, from Latin vitiatus, past participle of vitiare “to make faulty, injure, spoil, corrupt,” from vitium “fault, defect, blemish, crime, vice” (see vice (n.1)). Related: Vitiated; vitiating.