The term 'Shield Boss' can be summarized as a person who is in charge of protecting and defending a group or organization. The crossword solution for this term is 'UMBO, ' which is a type of metal shield boss used in the Middle Ages. It was typically made of iron and had a convex shape, with a central knob or spike in the middle. It was used to protect the hand of the warrior holding the shield, and also provided additional protection against arrows and other projectiles.