Definition of "vitiate"

The least admixture of a lie, -- for example, the taint of vanity, the least attempt to make a good impression, a favorable appearance, -- will instantly vitiate the effect.

1838, Ralph Waldo Emerson, An Address delivered before the Senior Class in Divinity College, Cambridge, Sunday evening, 15 July, 1838

Such diversion as Podson could extort from his isolation was soon vitiated by repetition. He surfed. He sun-baked - with discretion till his skin had peeled and given him a harder cuticle.

1938, Norman Lindsay, Age of Consent, 1st Australian edition, Sydney, N.S.W.: Ure Smith, published 1962, page 90

‘Mr Rose,’ says the Physician, ‘this man was brought to us from Russia. Precisely such a case of vitiated judgment as I describe at length in my Treatise on Madness. Mayhap you have read it?’

1997, Andrew Miller, Ingenious Pain

Unfortunately, as Anderson and Sørenson (1996) and Bowsher (2002) document, instrument proliferation can vitiate the test.

2007 August, David Roodman, “A Short Note on the Theme of Too Many Instruments”, in Center for Global Development Working Paper 125‎, page 9

We have examined with care all known negative feedback mechanisms, such as increase in low or middle cloud amount, and have concluded that the oversimplifications and inaccuracies in the models are not likely to have vitiated the principal conclusions that there will be appreciable warming.

2010, Naomi Oreskes, Erik M. Conway, quoting J. Charney et al., Carbon Dioxide and Climate […] , National Research Council, 1979, quoted in Merchants of Doubt

Dissolute and vitiated alike, they confided in, and ever acted in mutual concert with each other's plans, according to the deep subtleties of their reasonings, which linked them together by some secret spell.

1838, [Letitia Elizabeth] Landon (indicated as editor), chapter III, in Duty and Inclination: […], volume III, London: Henry Colburn, […], page 25

There was excellent blood in his veins—royal stuff; though sadly vitiated, I fear, by the cannibal propensity he nourished in his untutored youth.

1851 November 14, Herman Melville, chapter 12, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley

The robber does not intentionally vitiate people, but the governments, to accomplish their ends, vitiate whole generations from childhood to manhood with false religions and patriotic instruction.

1890, Leo Tolstoy, The Slavery of Our Times

‘Crush the cockatrice,’ he groaned, from his death-cell. ‘I am dead in law’ – but of the girl he denied that he had ‘attempted to vitiate her at Nine years old’; for ‘upon the word of a dying man, both her Eyes did see, and her Hands did act in all that was done’.

1965, John Fowles, The Magus

[…] all the hinges of the animal frame are subverted, every animal function is vitiated; the carcass retains but just life enough to make it capable of suffering.

1734, William Stukeley, Of the Gout, page 78

He went over his canvases with disgust and anger, unable to see virtue in any one of them. Even his sacred Oyster Girl went back on him. The creature of a vitiated æstheticism, he could only suppose that conceit had played an abominable trick on his eyesight.

1938, Norman Lindsay, Age of Consent, 1st Australian edition, Sydney, N.S.W.: Ure Smith, published 1962, page 133

After the trials, Turkey's secular elite was completely vitiated.

2011 September 2, Dexter Filkins, “Turkey's Thirty-Year Coup”, in The New Yorker‎