protector

/prəˈtɛktər/
noun
  1. A person or thing that keeps someone or something safe from harm or danger.
    • A good sunscreen is a protector against harmful UV rays.
    • The older brother felt it was his duty to be a protector for his younger sister.
    • The lifeguard acted as a protector for swimmers at the beach.
  2. A device or covering used to prevent damage or injury.
    • He wore a mouth protector while playing football.
    • A surge protector keeps your electronics safe during a power outage.
    • The phone case is a sturdy protector against drops and scratches.