a protective covering or structure
"The thick layer of wax acted as a shield, protecting the delicate fruit from the harsh winter sun."
Anything that protects or defends; defense; shelter; protection.
"The thick steel shield protected the soldier from the enemy's arrows."
A broad piece of defensive armor, held in hand, formerly in general use in war, for the protection of the body.
"The knight raised his wooden shield to block the enemy's spear before charging forward."
In plain English: A shield is an object used to block attacks and protect someone from getting hurt.
"The old car has rusted metal shields protecting its headlights from rain and debris."
Usage: Use shield to refer specifically to a handheld protective device rather than abstract concepts like safety measures. It is often confused with "screen," but while a screen blocks visibility, a shield actively deflects physical harm.
To protect, to defend.
"The knight raised his shield to protect himself from the incoming arrows."
A surname.
"My cousin, who shares my last name Shield, is a talented painter from London."
The word shield comes from the Middle English scheld and Old English scield. It ultimately traces back to a root meaning "to cut or split," reflecting how early shields were likely crafted by splitting wood.