catharsis
emotional purging
Today this word meansThe washed-clean relief of pent-up feeling draining away.
The word Aristotle used in the Poetics to define tragedy — it arouses pity and fear, and washes those emotions out.
Katharsis was originally a medical term for purging the body, and the name of religious rites of purification.
Worth noting
Whether Aristotle meant medical purging or religious purification has been argued for two thousand years — he left one sentence and no explanation.