contaminate

v.

contaminate means to make impure, unclean, or unfit for use through contact or addition milk contaminated by radioactive fallout; taint emphasizes effect over cause and implies that some measure of decay or corruption has taken place tainted meat; pollute implies complete befoulment through contamination, and now often suggests an impairment of purity that makes something injurious to health; defile implies pollution or desecration of that which should be kept pure or sacred