Untainted, a word that refers to something being pure and free of contamination, is an antonym for several different words. Words that are opposite in meaning to untainted are tainted, corrupt, polluted, dirty, and foul. Tainted refers to something that has been contaminated or corrupted, while corrupt implies a moral decay or unethical behavior. Polluted relates to something that has become unclean due to the addition of harmful substances or elements. Dirty and foul deal with physical cleanliness or a lack thereof. All these antonyms cause damage and reduce the value of something, the opposite of what untainted stands for.