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to be violated; to be corrupted; to be polluted; to be stained
「汚れる」 has another reading with different meanings.
悪い友達と付き合って心が汚れてしまった。
My heart has been corrupted.
誰かが落書きをして神聖な場所が汚れた。
Someone did graffiti and defiled the sacred place.
汚れのない心を持ちたい。
I want to have an untainted heart.