1to be purified; to become cleansed — used for physical purification or for a heart/space becoming pure or cleansed (intransitive).
手水で手を洗うと心が清まる気がする。
After washing my hands at the cleansing basin, I feel my mind is purified.
雨が上がり、空気が清まった。
After the rain stopped, the air became purified/fresher.
神事の後で社殿が清まったと伝えられている。
It is said the shrine was purified after the ritual.