a covering that is intend to protect from damage or injury

protect, hide, or conceal from danger or harm

a rubber or plastic shield to protect the nipples of nursing women

a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners)

a shield of lead or concrete intended as a barrier to radiation emitted in nuclear decay

shield consisting of an arrangement of metal mesh or plates designed to protect electronic equipment from ambient electromagnetic interference