- Betrayal of or treachery towards a man's lord. Such a betrayal by a *thegn in the AS world dominated by lordship and the imperatives of loyalty was a great crime, since all members of a lord's household were bound to him by mutual oaths. [< OldEngl. hlaford = lord, master + swice = treachery, deceit]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.