A natural or artificial purgation of any passage, as of the mouth, bowels, etc.
2.
(Psychotherapy) The process of relieving an abnormal excitement by reestablishing the association of the emotion with the memory or idea of the event that first caused it, and of eliminating it by complete expression (called the abreaction).
... in language with pleasurable accessories, each kind brought in separately in the parts of the work; in a dramatic, not in a narrative form; with incidents arousing pity and fear, wherewith to accomplish its catharsis of such emotions. Here by 'language with pleasurable accessories' I mean that with rhythm and harmony or song superadded; and by 'the kinds separately' I mean that some portions are worked out with verse only, and others ... — The Poetics • Aristotle
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