The word "unstained" refers to something that is clean, clear or free from blemishes or marks. The antonyms or opposite words of this term may include stained, tainted, soiled, contaminated or dirty. These words suggest a surface, fabric or object that is affected by negative influences, is not hygienic or is polluted. Alternatively, antonyms for "unstained" could be words such as blemished or spotted, which describe something that is visibly marked or flawed. Whatever the context, unstained is typically used to suggest cleanliness and purity, and its antonyms imply the opposite.