taint

Concise Oxford English Dictionary © 2008 Oxford University Press:
taint/teɪnt/

▶noun a trace of a bad or undesirable quality or substance.

■ a contaminating influence or effect.

▶verb

• 1 contaminate or pollute.

  ■ affect with a bad or undesirable quality.

• 2 archaic (of food or water) become contaminated or polluted.

– derivatives
taintless adjective (literary).

– origin ME (as a verb in the sense ‘convict, prove guilty’): partly from OFr. teint ‘tinged’, based on L. tingere ‘to dye, tinge’; partly a shortening of attaint.