noun: one who breaches societies rules, habits or accepted biases in such a way that the exact act of the breach cannot be described in polite company with also breaching societies rules, habits or accepted biases.

verb: for an individual, group or experience to corrupt an individual or group in such as way that they become perverted.

see also: perverts; perverted; I am not a pervert; sorry for being a pervert; thinking pervert;
compare: perverse;

In practice this pervert is a synonym for sexually perverse.

perverting the course of justice: verb: to knowing take steps to interferr with the outcome of legal proceedings. Typically by threatening witnesses, misplacing evidence, failing to disclose evidence, or similar. Hiding evidence prior to it's discovery by the police is not perverting the course of justice, that's being an accessory after the fact (disclaimer: I'm not a lawyer and this is not legal advice).