As a Noun:
1. A person or thing that protects or defends anything. English = protector, defender, guard.
2. A person who protects famous or important people. English = bodyguard.
3. A person or thing that protects patrons inside a nightclub or party from unwanted or uninvited guests. English = bouncer.
4. In team sports, team positions and team manoeuvres designed to protect the team from attack by the other team. English = defence.
5. In football, hockey or rugby, the player who plays close to the goal or line that he or she is defending. English = full-back.