Post by t***@gmail.com It seems clear that Gewissae is Anglo-Saxon and probably means "of knowledge" or "having knowledge" or "wise" perhaps in the way of skill or craft.
https://en.wikipedia.org/wiki/Gewisse
-- John W Kennedy "Compact is becoming contract, Man only earns and pays." -- Charles Williams. "Bors to Elayne: On the King's Coins"