vitiate

 
Pronunciation: /ˈvɪʃɪeɪt/

verb

[with object] formal
  • spoil or impair the quality or efficiency of: development programmes have been vitiated by the rise in population
  • destroy or impair the legal validity of: the insurance is vitiated because of foolish acts on the part of the tenant

Derivatives

vitiation

Pronunciation: /-ˈeɪʃ(ə)n/
noun

vitiator

noun

Origin:

mid 16th century: from Latin vitiat- 'impaired', from the verb vitiare, from vitium (see vice1)