taint

noun
A contamination, decay or putrefaction, especially in foodA mark of disgrace, especially on one's character; blemishTincture; hue; colourInfection; corruption; deprivationA marker indicating that a variable is unsafe and should be subjected to additional security checks.

verb
To contaminate or corrupt (something) with an external agent, either physically or morally.To spoil (food) by contamination.To be infected or corrupted; to be touched by something corrupting.To be affected with incipient putrefaction.To mark (a variable) as unsafe, so that operations involving it are subject to additional security checks.To invalidate (a share capital account) by transferring profits into it.