Words / C2

VISH-ee-ayt/ˈvɪʃieɪt/

To vitiate is to spoil something so that its quality or legal force is weakened: one false claim can vitiate the argument. Spoil and weaken are everyday; invalidate is the legal cousin (make void). It is a lawyers’ and philosophers’ verb. In speech, always say spoil, undermine, or make it invalid. If you use vitiate, keep the rest of the sentence simple so the reader is not fighting two rare words at once.

Meaning

To spoil or weaken the quality or legal force of something.

Examples

• “One false claim can vitiate the whole argument.”
• “Bias in the sample vitiates the conclusion.”
• “A forged signature would vitiate the contract.”

Good to know

Formal/legal: spoil or make legally unsound. Everyday: undermine / invalidate. Rare in speech.

Near in meaning

invalidate

New