The definition of a shield is a person or thing that protects, blocks, guards or defends.(noun)
See shield in Webster's New World College Dictionary
Origin: ME schelde < OE scield, akin to Ger schild < Gmc *skild- < IE base *(s)kel- > shelf
See shield in American Heritage Dictionary 4
Origin: Middle English sheld
Origin: , from Old English scield; see skel-1 in Indo-European roots.
Learn more about shield