person who protects one or several people from physical attack

A bodyguard is a security guard who physically protects a person against injury. Very often, important people, like heads of state, religious leaders (i.e. the Pope), actors, and powerful or rich people have bodyguards.

Two bodyguards, protecting the Turkish Prime Minister Recep Tayyip Erdoğan during Hannover Fair 2007
Bodyguards of Viktor Yushchenko (far left) after leaving Gdansk city hall.