자정이 · 자정을
self-purification, self-cleansing
Example
강물은 스스로 깨끗해지는 자정 작용을 해요.
River water cleans itself through self-purification.
Word parts
자 self+정 clean
Literally 'self-cleaning'; used for nature and for organizations reforming themselves.
Good to know
Homonym: 자정 meaning 'midnight' is far more common in daily life.