/ pəˈvɜːʃn; NAmE pərˈvɜːrʒn/ noun [ U , C ]
1.
behaviour that most people think is not normal or acceptable, especially when it is connected with sex; an example of this type of behaviour :
sexual perversion
sadomasochistic perversions
2.
the act of changing sth that is good or right into sth that is bad or wrong; the result of this :
the perversion of justice
Her account was a perversion of the truth.
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WORD ORIGIN
late Middle English : from Latin perversio(n-) , from the verb pervertere turn about, from per- thoroughly, to ill effect + vertere to turn.