Definition of tainting:
(n) :
A contamination, decay or putrefaction, especially in food.
(n) :
A tinge, trace or touch.
(n) :
A mark of disgrace, especially on one's character; blemish.
(n) :
(programming) A marker indicating that a variable is unsafe and should be subjected to additional security checks.
(v) :
(transitive) To contaminate or corrupt (something) with an external agent, either physically or morally.
(v) :
(transitive) To spoil (food) by contamination.