A number of offences are treasonous.
Things like slotting the Prime Minister (although to be honest, slotting the current PM would get you a national round of applause and a knighthood), broaching the wife of the King or future King and selling state secrets.
It used to be one of the few things you could still get the death penalty for in the UK, along with Arson in a Naval Dockyard and Piracy. Sadly, not any longer, which is bound to be a relief to traitors everywhere.
|Find out more in the Dictionary|