pollute

contaminate, taint, pollute, defile mean to make impure or unclean. contaminate implies intrusion of or contact with dirt or foulness from an outside source <water contaminated by industrial wastes>. taint stresses the loss of purity or cleanliness that follows contamination <tainted meat> <a politician's tainted reputation>. pollute, sometimes interchangeable with contaminate, distinctively may imply that the process which begins with contamination is complete and that what was pure or clean has been made foul, poisoned, or filthy <the polluted waters of the river>. defile implies befouling of what could or should have been kept clean and pure or held sacred and commonly suggests violation or desecration <defile a hero's memory with slanderous innuendo>.