To purify or cleanse (a person, place, or thing), often in a religious or ritual sense; can also mean to exorcise or ward off impurities.
神職が家を清めるためにお祓いをした。
A Shinto priest performed a purification ritual to cleanse the house.
海で心を清めるつもりで朝泳いだ。
I went swimming in the morning intending to cleanse my mind.
新しい仕事を始める前に、気持ちを清める必要がある。
Before starting the new job, I need to clear my mind/purify my feelings.
古い神社では、参拝者のために手水で手を清める習慣がある。
At older shrines there is a custom of purifying visitors' hands with water.