Source : Webster's Revised Unabridged Dictionary (1913)

Shield \Shield\, v. t. [imp. & p. p. {Shielded}; p. pr. & vb. n.
   {Shielding}.] [AS. scidan, scyldan. See {Shield}, n.]
   1. To cover with, or as with, a shield; to cover from danger;
      to defend; to protect from assault or injury.

            Shouts of applause ran ringing through the field, To
            see the son the vanquished father shield. --Dryden.

            A woman's shape doth shield thee.     --Shak.

   2. To ward off; to keep off or out.

            They brought with them their usual weeds, fit to
            shield the cold to which they had been inured.
                                                  --Spenser.

   3. To avert, as a misfortune; hence, as a supplicatory
      exclamation, forbid! [Obs.]

            God shield that it should so befall.  --Chaucer.

            God shield I should disturb devotion! --Shak.

Source : WordNet®

shielded
     adj : used especially of machinery; shielded to prevent injury