The phrase "pure as driven snow" represents a state of perfect cleanliness and innocence. However, antonyms to this phrase include "dirty," "tainted," and "corrupt." "Dirty" refers to the opposite of cleanliness, while "tainted" means contaminated or spoiled. "Corrupt" implies that something has been compromised by dishonesty or immorality, and therefore lacks purity. Other antonyms include "impure," "polluted," and "defiled." These words describe a state of contamination, imperfection and moral ambiguity - the opposite of the pure and pristine image evoked by the phrase "pure as driven snow.