freak mcnasty Share definition Flag Freak mcnasty is another way of calling someone a nasty freak, but saying it in a humorous way without offending them. Jay: I love when girls like my asshole! Nene: Omg!! You are such a freak mcnasty! freak mcnasty by Love~Neezy July 2, 2009 Get the freak mcnasty mug.