#2: Hand of the King

Throughout world history, many kings have trusted in a top advisor or confidant. In Westeros, this top position is known as the Hand of the King.

The Hand of the King is appointed by royal decree to execute the king's command. If the king is absent or indisposed, the Hand makes decisions in his place. As the popular saying in Westeros goes, "What the king dreams, the hand builds."

This use of hand isn't specific to Westeros: it's likely based on medieval English uses of hand that refer to someone or something that is an agent of authority. This use of hand also shows up in phrases like right-hand man or right-hand woman.