A mad or foolish person.Or in some cases, they were just complete borderline nutcases with sociopathic tendencies....
Neil Pickup would probably not welcome the reference: ‘People want to portray us as nutcases or beer-swilling madmen and the sport as just a pub game with no skill or no strength.
And that was the central argument of the first wave of books about Eichmann; that the guy's basically a weirdo, a pervert, a nutcase.